exact same situation here. don't make him choose, then he'd choose her..
if she makes him choose, then maybe, just maybe, he'd choose you over her.. but he'll still want the V from someone..
have a chat with her! and stop cuddling him, i backed off when mine got a gf
i keep my distance with him now, we're still best friends but i let him make the effort because if i do something, it pisses the gf off (which is kinda funny lmfao, she's so insecure)