Found out about other girl while on road trip PLEASE HELP!?

Me and my boyfriend recently took a trip to california from denver colorado while on vacation I was using his phone and got a scandalous text from a girl I then went through his phone and saw that he was flirting with three other girls. One girl he met a club and she was sending him pictures the other girl he was saying stuff like "i miss you babe" and the the third girl he was calling also it hurt my feeling even though he denied cheating saying he just talked to them never saw them. So now I am at my bestfriends mothers house (he stood in the motel) and about to head home on an airplain i have to pay for because i can't stand being in the car with him he does want me to forgive him though do you think he really could just be talking thanks i am just so hurt by this situation i thought we were really happy