I may have hooked up with a guy who has a girlfriend and I feel awful?

[Mardy.]

I met this guy (a traveller) one week ago. We went out almost everyday during the week. We partied on saturday and on this sunday, we also stayed together.
To be honest, I was expecting that he would take some action but all we did was kissing and cuddling.
Of course I loved it but my friends say that it is very weird that we didn't have sex and that he probably had a girlfriend.
He said he didn't have one but I saw some pictures of a girl on his facebook.
I know it doesn't matter anymore, he is gone and we won't see each other again but still I feel terrible only by imagining that he cheated on his girlfriend.
And yeah, I also feel a little rejected. I can't explain.
Please, help me.
And I know I would feel worse now if we had had sex.