My boyfriend gave another girl a massage?

[Laurie C]

My boyfriend came to visit me at school he left his phone on my desk and went to take a shower, a few seconds later a mutual friend of ours (shes a girl) kept sending texts to my boyfriend. I picked up his phone to reply saying that he was in the shower and to ask how she was cause ive been away at school and i missed her. I read the text and it said "Oh my god im so sore I need you to massage me like you did last night." I was upset! what the hell! he came back from the shower and I just started yelling at him. He claimed he did it for travel money so he could come see me. How would any of you deal with this? Ive been with him for 3 and a half years and i love him so much, but right now i feel so betrayed and hurt. He says he sees nothing wrong in the fact that he was doing it for money! i dont know what to do! the girl is single and has made her attempts to get with my boyfriend before we were dating/
thanks Karl. This happened over the weekend, so i have calmed down, quite a lot. I would have preferred if he had said i am broke and remained faithful. I would have gone home to see him, i was planing on it but he insisted that he come up. He would have never of told me about this if i didnt read his texts. So i dont know if i can trust him. I couldnt really talk to him while he was at scholl with me my roommate was in the room so we left and friends joined us and we hung out, again he left his phone to go to the bathroom and low behold he was texting her! He said: "I cant im out of town" not no i cant im in a committed relationship and i am visiting my faithful girlfriend! He's lying to her too!