David's apartment number is 101 when Leila leaves, but when the blonde girlfriend leaves, it's 116.
In the scene where Leila and David are about to have sex on the couch, after he takes her panties off he puts on a condom. After a minute or two they roll off the couch and onto the floor where they finish having sex. After she stands up he is still laying on the floor and his penis is clearly visible with no condom on it.
When Leila is performing oral sex on a stranger she meet in
the club, she pulls his pants and undergarments down to the ground. In the next shot, his pants are up around his waist again (with the fly open). The third shot shows his pants around his ankles once again.