One likes to encourage and participate, one likes to put down and humiliate

They rarely come over together and they are total opposites about my masturbation. Beth is a total tease and encourages me and rubs her tits on me, Vicki totally humiliates me and laughs at how much I masturbate... The strange part is I'm not sure which I like more, they both turn me the fuck on!! I have a better relationship with Beth but that is not only because she is more friendly but she also comes over much more often. Vicki only stops by if she needs me to do something for her, Beth stops by whenever she wants, sometimes several times a day... 

I'm hoping that they don't move after this semester is done, and if they do hopefully they will still stop by from time to time.....