Love is Blind it always is and you can go blue in the face trying to help him out but I guarantee he wont listen.

I mean, shit, when I have been in that situation like my last ex I listened to no one. Then that all went tits up and she nearly ruined my life!

Seriously fella, be his mate, be there to pick up the pieces, but don't mess with any guy when it comes to a woman they want to be with. They wont listen and you'll fall out if you keep it up.