You have every right to be offended tbh. Showing someone you know your work is a thing of trust. Stranger are one thing, you don't know them, don't have to deal with them every day and speak to them casually. But with someone you know and are close with it's very different. And this was a really dismissive comment.
I've had friends look at my work, especially when I was publishing short stories ect back in the day I'd ask my mum to proof read them, and that was a massive step in trust because they were not her thing at all (in fact they were probably things most people would be embarrassed to show their mums) and she at least had the decency to say "it's not my thing but I'll tell you what I think as objectively as possible" with the understanding she wasn't the target audience. On the other extremeend I asked a friend to look at some designs for a project, I showed them one character design with just a name and got "oh not another story about a cishet white dude" and yeah that really offended me and I never asked them for advice ever again.
Unfortunately, when it comes to people you're close with those are your options. Talk to them and tell them that was a pretty insensitive if not down right rude thing to say and hope they understand, get mad and never ask them for advice again, or ignore it and just try to carry on. Now I'm older, I'd say at least try to talk to them and explain why it hurt you, or they'll just end up doing it again. There's a difference between "it's not really my thing" and "get to the thing I want you to do", after all, especially if you're just asking advice, not for them to like it. Comics and similar projects tend to be like their creator's baby after all and I doubt many people would go "I'm not interested in this child, have one I'm interested in".
In my experience, ignoring it and carrying on when you're hurt, even if they didn't mean to hurt you, can lead to festering and getting worse.