Also why are you looking down on your friend H for getting back with someone as awful as C but you were involved with C ("what her gf doesn't know what hurt her?" Seriously you did that to H by being involved with C?) and your other friend is sexting her right now according to your post? So you're cool with your other friend dealing with this C person as well even though you guys know she's lying and manipulative?

Unless I'm reading this totally wrong, I wouldn't be throwing stones in glass houses if I were you. You say love your friend but you still chose to be involved with her crappy, manipulative ex and you don't seem to care that your other friend is also choosing to be with C.