How to tell if he's real or not? What should I do...?

Ok, so picture this: You've been talking to this one guy for months, since March (lets call him Rob). So you've known Rob for months, and then you think you really like, like online bf like him. Then you meet one of his best friends.. (Lets call him Sam), and you like Sam even better. Infact, you and Sam are actually REALLY alike, and you get on REALLY well. You speak to him for months also, and you become like best friends. You talk everyday, and the conversation just flows. You can talk about ANYTHING. Then, you get Rob's number and have no suspicions. Next thing, you start talking to another girl whos been talking to Sam.. you get her to give you Sams number.. and its the same one that you have for Rob. "They" come up with some story about Rob not wanting to give you his number because he was "afraid he'd get too attached".. So you believe them. Then you start noticing really weird things about them all these friends, that they have on bebo. Some of the people in their pictures are named differently to what they're named in the others etc. THEN you find out that Sams number is actually Irish, and several of the gigs he's been to were in Ireland... ?? Is he Irish?? However, i've been in a 3 way convo with Rob and Sam, and also i've spoken to their friend "Jess" on the phone, and she sounded completely american. HELP?