Check this out mane... when an ex loses feelings for you, she goes ICE cold. She doesn't deal with you at all. If she wasn't digging this negro to some extent, she wouldn't answer his calls or respond at all. All you know is what she's telling you, but you need to think... what kind of conversation transpired beforehand for him to even invite her to a party in the first place? You need to make her put it on the line. Tell her to handle it like this," Look here, don't take any more of his calls and that whole situation is deaded." If she brings him up again, time to move on. The fact that the brother hates him but somehow the ex is steal dealing with her ain't a positive sign. Sounds like one of those situations where the ex keeps popping up in her life and the brother has to deal with all the nonsense from the eventual fallout. If your woman can't respect you and wants to play around on the phone it's time to tell her to get gone.