Frenemy

Someone that you think your friends with but as soon as they've got a boyfriend they'll leave you quicker then you can breath. They'll apologies and say sorry afterwards when you confront them but they do it again after wards they'll later come back when they break up and expect a forgiveness.

Me: were going to shopping you wanna come?
Frenemy: sure I'll come.
Later that day
Frenemy: sorry can't go I'm going to do something with my boyfriend.