I HIGHLY SUSPECT THAT MY BF HAS BEEN CHEATING ON ME - HELPPPPPPPPPPPPPPPPPPPPPPPPPPP…

I highly suspect that my bf has been cheating on me with this girl. He denies it so I friended the girl on fb under my best friend's account and I'm acting like I'm a new girl who just moved to the area from FL because of my dad's new job. So we are talking about FL (where I moved from) and Arizona (the current area). She writes long paragraphs, but I can't figure out how to bring up my bf subtly like what should I ask like, "any cute boys in the area?" or something haha. Will that look obvious? What do you think? Thx