Catch him cheating?

Would anyone be willing to add my boyfriend on Facebook and contact him/flirt with him so I can ease my mind on whether or not he's being faithful. He seems distant and doesn't seem to ever talk to me but he's constantly active on Facebook but never posts anything. I know if I ask him he'll deny it and the only way for me to ever find out is if I catch him doing it. I know I should trust him but I can't help the nagging feeling so can someone help a girl out? Preferably someone 17-19 and if anyone is on any dating websites/apps would you mind looking him up for me to see if hs on there