i dont think christy is looking for love, all she want is all the attention on her all the time, now she is alone and julia seems to enjoy the attention a lot , may be she finds them a treat in that aspect.
she entrapped them for the last 3 days every time they are having their time in the bed room she start talking to them or for one reason or another she walks in to the bed room, beside she could have taken her bath and masturbate any time, but she always seem to choice the time when they are in bed, it might be innocent but knowing christy it makes you think of her motives.
from what i observed this girls don't think girl and girl making out as sex just fun play may be because they consider themselves as strait may be that does not count , so one of this days they get really drunk and the girls start playing that will lead to him joining, if that happen the next morning 3 things would happen 1. the relationship weaken or break between gavin and julia, 2.the apartment become a very awkward and people stop taking to each other or 3. they think it was fun and carry on which all three lead to trouble in time as we saw before.