Chill out and have trust in him. You'd hope he'd have trust in you as well right?
I went on holiday with 3 female friends while our boyfriends were all away on a lads holiday. 2 of the girls were so paranoid all the time and could not stop texting and checking up on their boyfriends. It was literally all they talked about for the whole holiday. Don't be those insecure girls, it's more likely to push your boyfriend away if he can see you're needy, insecure and have no trust. Be confident in yourself and the great relationship you have. Don't mother him and give him a curfew and expect him to text you back immediately every night. I'd suggest keeping yourself busy while he's away and keep in touch via snapchat or something so you can have peace of mind that you know he is where he says he is. I'm sure he'll understand why you're a bit concerned as he has previously cheated so just tell him to keep you updated so you know he's safe. He might be very keen to prove to you that he's a good loyal boyfriend. Let him enjoy his holiday though, don't be his nagging mum.