YTA

Sure, periods can be a little gross. Want to know what else is gross? Shit and piss. Do we make a big deal about shit and piss even though it's dirtier and shit has deadly potential? No. There's no reason to make a big deal out of periods.

To show how nonsensical this is, I replaced "period" with "poop"

“I don’t find pooping gross and you know that. But I don’t think it’s unreasonable for someone to say that they find pooping gross. When I say that, I’m not talking about the actual act of pooping. I think everyone understands that it’s perfectly natural and nobody cares about actually pooping, you know? It’s just the stuff that comes with pooping. Some people are squeamish about poop and for them it’s gross to even think about that stuff. That’s why I can imagine why someone would think that poop is gross and I don’t think I can demonize them or call them childish for that. Even if you may not think it’s rational, people have much worse phobias and we don’t demonize them for that and I feel like this shouldn’t be any different, as long as they’re not shaming a woman for pooping then i feel like it’s okay to be a bit grossed out by them”

Obviously, poop is gross, but if someone got upset over someone pooping, they'd be seen as weird. Same with periods. It is childish to act all gross and squeamish over it. If periods bother you so much, then just don't ever be with a woman. Problem solved. Otherwise, don't act like it's ok to be a grossed out child over blood when that shit that comes out if your asshole is way grosser.