THE DRAMA!!!!! - advice

So here's the thing. One of my best friends is head over heels for another one of my best friends. She used to like him but doesn't anymore. And he's been bugging me for advice but I can't really think of anything. I keep saying that a part of her might still like him but he's reinforcing the MIGHT part. And also it's like I want to help him but I don't want to make her feel uncomfortable. Can anyone help please?