Hi, Trac,
I am going to suggest you play an imaginary game right now and reverse the situation. What IF YOU were the one doing this...having a summer boyfriend with whom you share a bed, telling your college boyfriend you're just good friends, and going on vacations with this summer boy. You wouldn't do that, would you? And you would know this wouldn't be right for the relationship with the college boy, not moral, not honest, and even hurtful to him. This is what this boy is doing to you!
If you were my daughter, I"d be trying to persuade you to end this relationship with the college boyfriend, and no apologies or explanations are necessary from you! He has played you, and he has been emotionally cruel!
Do the best thing for you, sweetie!
Patty