Bf said give him time?

Ok, my bf and I have been together for 3 yrs. We live n atl. I am currently back at home n ohio temporarily til june to work. Ups and downs like all relationships. Recently we both discovered some "messing around" was going on. During a period of time when we were saying "we're together but we're not". I not physically cheating, but he did. The incidents happened mths ago. But I revealed mine, he got caught. We're healed now. Jus came back from a trip together and had a great time. He tells me yesterday (after a great w/e together) that the thought of me messing wit this guy again is tearing him up. And he has all these diff things (actually named reasons y to me and they're reasonable) about it running through his mind. He says he needs time to get it outta his head. Mainly bcuz the guy lives n the same city where I'm at nw. Says we can still hang out because he "loves me to death and I'm gonna b his wife" and all that but its ok 4 me to talk 2 other ppl. Watta u think? I think its stupid. And I'm nt understanding how this is a logical solution for this. My mindset is pretty childish. I'm like well u know wat this is ridiculous and I'm jus nt gonna contact him unless he calls me. How should I handle this? (Btw we're 23 so its nt like a juvenile relationship)