Cheating through and through in my opinion. Emotional cheating I'd the worst kind of cheating.
Yeah. I just generally dont trust anything he says about past girlfriends, since some of them have been close friends of mine, and he always just spills the vilest things about them once the relationship ends which I know to not be true. He also tends to talk about their sex-life, which I find to be just disgusting. (not because like ew sex, but because he is spreading this crap about without their consent and I feel so bad for the girls. And some of the crap is just made up, like one he would just talk on and on about how the girl liked anal and would pressure him into it but he thought it was gross and like A) why the f are you telling this to your little sister and B) again just a really vile thing to do)
I do love my brother obviously but I also just like would not be around him if he was not my brother if you get me.
Like I'm not saying I'm some saint either, I talk some shit about people a ton too, exes especially, like how one of them was a chainsmoker and that grossed me out, but I would still never spread any intimate details or things that they told me privately because I feel like even if things end badly you should always just have some form of idk reverence to the relationship you had and keep that crap to yourself. Friends too. I know some shit about friends who I no longer keep but like I'd never spread that around.
I honestly hate terms like emotional cheating and mircocheating. Mostly because these sorts of terms are used 99% of the time to try and manipulate and control. They're most often applied to perfectly normal interactions between friends of opposite gender and sometimes even of same gender. Things like how dare you text someone else while I'm in the room, how dare you have plans with someone else, why are you spending time alone with them, why do you tell them things you don't tell me ect. It's perfectly normal for friends to hug or hold hands or join arms or kisses on the cheeks ect but some people will consider this mirco or emotional cheating because how dare you not consider your partner the be all and end all in your life. It's controlling and manipulative attentions to get someone to themselves and guess what relationships where you and your partners and theirs alone are not healthy.
I had a close online friendship with someone I'd never met in real life and their girlfriend accused them of cheating on her because they told me they were in the hospital first, despite the fact that actually I was talking to them while it happened and the girlfriend lived in a different timezone and was still asleep.
A lot of it comes down to simple boundaries. The example sounds a bit dodgy but simple things like knowing your partner well enough to know how they might react to a joke like that is important. Obviously relationships come in all different forms, and so cheating does too but we do have to be careful.
Fun fact: In America, we have a term "summer fling" which is the same idea. Why anyone would want a short-term casual romance or a random hook-up over a long-term relationship is beyond me lol
Anyways, yeah, dude put himself in that spot. It's not cool to make jokes like that while in a serious relationship, and on a separate note, jokes are just harder to convey through text alone..
But, is it over-reacting to break up over a series of texts? Maybe, but the dude sounds like he has a history of bending the truth in his favor. Even if that wasn't the case, you said he tendency to talk about his dating life to you, in great detail too. Maybe it wasn't a joke to approach that other girl, after all? I certainly wouldn't trust his word on this lol
If he's not broken up over this and makes no effort to fix that relationship, then that girl might've made the right move in calling it quits tbh
I get where you're coming from when they're used incorrectly, but I have to disagree in not using them at all as it's all too real. I had a friend in college I developed a sort of skinship with only to find out he had a long distance relationship. He was literally using me in place of his absent SO and I felt like trash because of it. I knew we weren't in a relationship but we'd confided in each other in intimate spaces and situations. When I found out he was dating someone, I felt used and disgusted. It ruined my relationship and till this day I can't interact with them.
I don't get mad when my SO has friends of the same/opposite sex (they're bi). I would get mad if they ended up a situation similar to mine because that's cheating to me. People who won't let they're SO have friends just because they're jealous are controlling garbage and have no right to be in a relationship. I will be angry if my gf flirts with a friend or some rando tho because it makes sense to be angry.
I mean what you're describing is just outright cheating really, unless they talked with their SO about it and definitely should have told you about it. That's entirely different to what people consider things like microcheating and emotional cheating. Let's not forget, mircrocheating (as far as I'm aware) was first coined in a womens magazine article describing how "if he's texting another woman at all it's a sign he's microcheating". And things like flirting is a personal boundary, some people don't mind some for. Some people are just flirty. Some people don't even realise they are flirting. That sort of thing is all about boundaries and talking to your partner and respecting each other.
I also think that your brother absolutely brought this upon himself. Considering, according to you, the apparent history of bending the truth in his favor as well as the fact that he brushed off the texts as "obviously being a joke", regardless of whether he was going to cheat more beyond said texts, it sounds like flirting.
Pardon me for saying this, but I hope your brother gets some sort of a reality check, lmao.
I understand your dislike and while I don't know how valid the term micro cheating is, I do think emotional cheating is a thing that happens. Emotional cheating is usually the more painful type of cheating, especially when the parties involved claim to be in a committed relationship. If you had a significant other who said they'd only be for you, then you find out that they were saying the same things to someone else, I feel like that would be more of a betrayal.
Back to the OP. If it's a joke, it's a joke. I think the issue here is him doing this behind her back. It doesn't seem like he made it clear to his girlfriend or the other girl involved that the "flirtationship" was a joke. If the joke was so obvious, why did he need to explain it? This probably a lack of communication, though I can't say that much given my ignorance about the two, I mean three people involved.
I'm finnish and kesäheila term is definitely something people I know wouldn't use when in a relationship. Not even as a joke. It's cheating and joking about it (if he's telling the truth) is weird. I'd definitely be suspicious and if his gf of 3 years left him for a few texts I think something else has been going on that you're possibly not privy to.
And since the rise of far right/PUA/red pill shit who knows, maybe your brother has changed a little? Spinning plates is a term used to describe dating many girls at the same time without telling any of them. Kesäheila fits perfectly here. Is he looking for a fling to spice up a 3 year relationship and got caught? Or maybe he's a good guy and all this is speculation. I mean no harm! I just see devils everywhere.
Ok I honestly just want to show you guys some of the things that genuinely come up on lists of "microcheating behaviors and warning signs":
- Your SO is taking care of their appearance.
- Your SO isn't letting you see their phone when you demand it.
- Your SO is going out without you.
- Your SO is excited to see friends.
- Your SO follows attractive people on social media
- Your SO is confiding in or venting to someone else.
- Your SO is sending someone else memes.
- Your SO asks someone who isn't you for advice
- Your SO has inside jokes with someone else
- Your SO closes their eyes when they "need a moment".
- Your SO does something nice for someone else
- Your SO tells someone else they're thinking about them when not their birthday/other event
- Your SO pays for things for their friends
- Your SO recommends things for you to wear
- Your SO has strong opinions about physical cheating.
All signs your SO is micro-cheating you should be aware they're probably outright cheating too. If you're showing an of these signs you're probably cheating too.
Good point (however, I don't know if it's applicable here).
I'm pansexual, and if I had to count the number of times people implied that I can't have a non-sexual relationship with anyone vaguely in my age group.. It's crazy how people will assume that if you may theoretically be interested in a person, you must be flirting with them. Thank you people for taking away from me the simple possibility of a friendship 
What I generally say to them (only work with straight people, also theoretically with 100% gay people but social pressure often do alter that somewhat), is that if the behavior is something they would do with the the gender they are not attracted to, that's likely NOT flirting, and vice-versa.
There are a lot of exception, and the personality of the person has to be taken in account, but as a general rule it works for guiding people about me and the fact I'm pan.
Yeah, that's what he thought he was doing. Something harmless, something flirty. I confronted him about it and he thought it was harmless because he's just 'naturally touchy with people.' It's why our relationship was r salvageable.
I feel like my situation was an example of small flirting and touches turning into just full blown cheating.
I personally hate the term "microcheating," because it minimizes the fact that it's still cheating. It's like it's trying to make it seem like they didn't actually cheat, they just cheated a little, so it's not as bad. "I flirted with another person and I kissed them once, but it's not like we had sex, so I'm not a total jerk."
But that is cheating. I've never seen anyone apply microcheating to that. Microcheating is "small, seemingly harmless things that you might not notice but are still cheating". See my post above for things that are actually considered microcheating by a lot of articles.
It depends on the relationship. I might be a little biased since I have some unusual views on relationships in general, but I see flirting as silly fun most of the time. That said, communicating your boundaries and comfort levels with your partner is paramount. Don't just assume they'll be okay with it, and don't be dismissive of their concerns. In the context of your brother and the way you've described him, I don't see it as a fun joke, just a bright red warning flag. His ex was right to be upset, and I have to wonder how he'd have reacted if their roles had been reversed.
I hate that term with a passion of 100 burning suns. It is either cheating or its not. Yes there are situation where is ambiguous like the ones above, however those are more of a communication issues that were already present . But your brother, no offense, seems like a bit of a tool and this might have been the straw that broke the camel's back, in a long line of problems.
Chances are the texts weren't the first offense. I dated a guy who was juggling so many random girls and whenever I confronted him about it (it was so freakin obvious on Facebook and everyone was telling me what he was up to, it was just so blatant) that he was like "Oh it's nothing" because he just wanted to have as many "options" open as he could. Anyways I got tired of being just another option, so I cut him off.
He thought it was over a smaller thing, because that was the thing the he was caught doing when I finally snapped and was like "this is done"--but it was only the straw that broke the camels back, so to speak. He had been a bucket of flirty problems with every girl he came in contact with since day 1.
And then he turned around and told everyone I knew that I was crazy for breaking up with him and it's like...no one even listened to him at that point they were like "yeah he's one of those." I doubt your bro is as bad as this particular guy was--this particular guy was unique in his douchiness--but firty texts are like cockroaches, you see one that means there's a thousand others hiding somewhere in your apartment.
I suspect that this wasn't her only reason to end a 3 year long relationship, but aside of that:
After 3 years I would suspect that he knows the limits of what is acceptable for his now Ex and what isn't. He crossed that line knowingly anyways and she is in the right to cut him off before the "joke" becomes reality.