Bathroom sex is when you have sex in the BATH. But more wet and dirty.
Warning might make you horny

I was home alone, because my boyfriend was still at work so I decided to take a bath. 5 minutes after the bath room door opens and my boyfriend Justin busts in gets into the tub and starts thrusting his huge dick into my pussy. "HARDER HARDER FASTER OOOHHH BABY" I yell. He cums then comes of my pussy. We get out and I drain the water, we walk in to the room and I start giving him a blowjob. He runs his fingers through my hair. "Stop. Wait lets get back in the tub." He says. He picks me up, and starts to make out with me. We get to the bathroom and slams me on the wall never breaking the kiss. He puts me in the tub then fucks me hard. I get on top of him and rides him like a horse. We do this for an hour, then falls asleep in the tub until we wake up and do it again.

I hope that helped u understand what bathroom sex is.
by I'm_a_sucker_for_dicks October 14, 2017
Commensing in hot doggy-style sex while in the bathroom of a fast food retaraunt. Usually a Burger King or McDonalds. Not wendys though. If done through the butthole even better.
"Me and my girl are going to Mcdonalds yo"
"Cool"
"And we'll hopefully have some bathroom sex my man!"
"NIce!. See you later dude"
by the adamsbobler February 19, 2009
if the female goes into the male bathroom the female was the one that wanted to get piped.

if the male goes into the female bathroom the guy wanted to pipe her.
guy 1: damn they doing it in the guys bathroom.

guy 2: damn she really wanted to get piped.
guy 1: what do you mean?
guy 2: if they’re doing it in the guys bathroom the girl wanted to fuck
guy 1: says who
guy 2: the urban dictionary, it’s the bathroom sex rules
by charlie perc March 26, 2020
Instead of a uni-sex bathroom it is a bathroom you have sex in.
"Hey, is that a uni-sex bathroom?"

Giving them bedroom eyes, "Nope, it's a "we-sex" bathroom"
by hippiedick February 7, 2010