co-datee
Two people who go on dates together but aren't in any official capacity
Yeah dude, we're co-datees
Co-Dating
When your roomie is dating someone for serious and they are around in the appartment as much as if you were dating her/him.
-OMG! Mike is bringing Tyra to the appartment all the time!
-Yeah man you're co-dating her .
-Yeah man you're co-dating her .
Co date
The practice of having two dates in close proximity without either of the knowing the existence of the other
Tonight im going to be tired because im having co dates one for dinner and one for a drink in the bar next door. I willl them i have stomach problems so i can move from one to the other