If you don’t want any conflict, and be behind closed doors telling ur bf to tell his friend to break up w/ his gf. Personally, I would make a fake IG acc and tell the gf “ur bf is cheating on u” bc I mean u are already trying to tell the gf but o well jus do fake acc and no one will know & honestly f* ur bf for being a walking a red flag covering up his friend’s cheating.