So I have a romance all from one POV and another from both sides. It's not inherently lazy to switch POVs if you want to show more of that person's life and story, but if you just want to convey clues, there are lots of ways you can do that without switching POVs.
- Show what they're thinking by their body language.
- Show what they're thinking by clues in their dialog (they can mention something that shows what they're thinking without explicitly saying it, for instance: when my male lead compared his relationship with the female lead to that of his parents, you can see that he's thinking about himself and his female lead in a romantic context rather than a platonic friendship. there are other examples of this I can give if you like.)
For me, it all has to do with getting into the characters mindsets. I often do this by daydreaming from different character's POVs and writing character design sheets to help me understand them better. My male and female lead have distinctly different narration styles, and while the whole story is from her POV, here is an example of a bonus chapter where you get to see his POV of an event you also got to see from her perspective:
This should depend on context. You don't really need to include key gendered things in most contexts, I think, and if you do I think this would be more subtle. It is realistic to weave it in, in my opinion, depending on the context.
An example of this from my writing is that on a first date in my novel "A Dozen Morning Glories" the female lead refuses to drink alcohol because she's nervous about the consequences of getting drunk with a (male) stranger, while when the male lead becomes aware that she's acting oddly (which has nothing to do with him) he's worried the waiters will think he did something to her.
So, there are contexts when gender will have a notable bearing on the plot, but it's not like, every single scene. It more has to do with: when will the cultural perception of your character's gender affect them? only in those contexts do I usually dwell on it.
One other example, is that the male lead of my novel "Damsel in the Red Dress" feels depressed after being paralyzed, not only because he can't move properly anymore, but because he's now dependent on his mother to care for him, while culturally, men are expected to be strong and not need any help from anyone. There's also the fact that his mother and her friends tend to think that most men are useless and a waste of time, and he doesn't want to live up to her negative expectations