New boyfriend...but trip with another guy

I have new boyfriend. And well I like him he’s treating me well. Well before we made it official I planned a trip with another guy I was seeing. Well me and him are official now...my boyfriend went on a guys trip and of course I get a little jealous and I’m like hmmm should I still go on the trip with the other guy even tho I have a new boyfriend. And my boyfriend is planning a trip with me for his birthday anyway. So should I just tell the other guy I’m taken or just say I can’t go and make up an excuse instead of telling him I have a boyfriend? 😂 I need sound advice thank you.