There are those nights when you truly just want to grab a beer (or seven), hang out with your friends, and complain about work. But then there are the other nights when you use up all your hair gel, iron your jeans, and truly just want to get laid. Once you spot a girl at the bar and reel her in with your subtle-yet-strong eye contact, you’ve began a modern day phenomenon known by scientists as the bar relationship. It can either either end right at that very bar or it can actually progress into a full-fledged committed relationship.

Level 1 – Flirtatious relationship

You say something insanely witty, she says something sexual back, and before you know it conversation is flying back and forth faster than the girl can keep adding her drinks to your tab. Either she signals her friends with a loud sneeze, gives you a phone number that starts with 1-800, and starts talking to another guy at the bar

Or you move onto …

Level 2 – A bar make-out session

Throughout the night your heads are getting closer and closer until finally the inevitable kiss happens. You both look at each other, laugh, and say I’m not really into PDA. Ten seconds later you’re having a full-on-hands-up-the-shirt make-out sesh that’s being filmed for a Youtube premiere by the creepy loner in the corner. Either she’s serious about not liking PDA and causes a huge scene by telling you to seriously stop

Or you move onto …

Level 3: Bathroom stall groping

Things are starting to get a little too hot and heavy for the bar and after hearing one too many whistles from spectators, you head towards the bathroom. Once that stall door is locked (and you drown out the angry yells from people in the bathroom line) bras come off and belts are loosened. Either you sneak out of the stall while she tries to get her heel unjammed from the toilet bowl…

Or you move onto …

Level 4: A one night stand

You bring her back to your place, give her a mini tour (point to the bedroom) and then put on the Marvin Gaye mix you made just for a night like this. Before either of you can go over each other’s names again, all clothes are off, and you’re praying your condoms aren’t expired. Either you snore loudly and pretend to be asleep as she prepares herself for the time-honored walk-of-shame

Or you move onto…

Level 5: A weekend fling

Neither of you want to get out of bed when you wake up in the morning. You bring up a funny story from last night, she shows you a weird shaped bruise she got when you couldn’t hold her up against the wall anymore.You spend the next two days tangled up in sheets sharing your life dreams, confessing your biggest fears, and coming up with a quality safe word. Either she takes the confessions too far and admits she was technically born a man

Or you move onto…

Level 6: Booty call

You can’t always recall where she’s from or what exactly she does for a living, but you do remember that she can do it in handstand position. Over the next month or so you call each other when either person is horny, lonely, and/or bored. Either you start to develop a strange rash that she explains away by saying that it will come and go for the rest of your life

Or you move onto…

Level 7: A serious relationship

Not only is she a cirque du soleil alum in bed, but you actually enjoy spending time with her doing other things like eating out at restaurants and holding hands in public. You’re just dying to meet her parents and you don’t get so angry anymore when she calls you by a cutesy nickname. Either this ends in a horrific break-up scene where the neighbors call the cops or you get married and entertain yourself for the next 50 years telling everyone that your wife was supposed to only be a one-night stand