A rite of custom widely practiced in both Europe and North America where two or more heterosexual male friends take a shower together. Once the participants are undressed and under the running water together, one or more of the men will pee on the chest of the other men present in a display of acceptance and trust. It is widely regarded as a faux pas to direct the urine stream away from one's showermate(s) (i.e. towards the drain) as it is generally perceived as an affront to the bonds of friendship.
In recent years, the bro shower has grown wildly in popularity and has mostly replaced the antiquated handshake as the standard way of bonding with another heterosexual male.
"You seem like a pretty chill dude. Why don't we go to my place for a bro shower together to make this friendship official?"