There's nothing childish, misogynistic or even anything remotely problematic about a guy not wanting to shower OR have sex with his girlfriend while she's on her period. He's allowed to have his own preferences that are not determined or REGULATED or SHAMED by his girlfriend, people on Reddit or mainstream society as a whole.

Him not knowing that the shower would most likely NOT look like a scene out of horror movie is indeed a bit childish and misinformed, lol. But lots of guys don't know this stuff unless they hear it from a woman or learn it first hand through experience as this kinda stuff is NOT covered in sex ed class and might not come up in daily conversations.

He didn't handle this situation in the best way but neither did his girlfriend. He didn't use any tact or situational awareness to communicate his thoughts and she immediately defaulted to a state of insecurity and gaslighting to get her point across.

I personally love and respect women, enjoy having sex and a physical relationship with them and I am empathetic to some of inconveniences of being a woman and I know that a period is a biological process that's essential to our ability to create life. But that still doesn't negate the fact that I'm also extremely turned off by the sight of a bloody vagina. And I'm smart enough to know that period blood is blood mixed with microscopic pieces of flesh (uteral lining...etc) and I just choose to avoid it if I can and I've been blessed to deal with women who understand this and don't judge me because of it.

Nuance is clearly a lost art with folks these days and the self righteousness and entitlement of folks who rush to judge others is an intellectual haphazard at best and flat out toxic is in lots of cases these days. Smh...