Promotes oxytocin release.

...but real talk, shower sexytimes seem fun and novel early on, but you learn pretty quick that the angles are kinda cumbersome, and the water dissolves the vaginal mucus that lets the slip-slidey-magic happen.

The wins here are 1) utility: we tend to need the shower around the same time, and this lets us use it at the same time without that awkward standing in the cold nonsense the OP's meme is highlighting; and 2) comfort: in addition to the absence of the standing in the cold nonsense, taking a shower solo and getting that warm water from both sides is like having your own jacuzzi - that shit is relaxing as fuck!