trip with boyfriends family

j

i need help on how to ask my parents if i would be allowed to go on a trip with my boyfriends family to chicago. We have been dating for almost 2 and half years and my parents love him but they are sort of strict. we have never had a sleepover (with there permission). I’m 17 and he just turned 18 the other day. My birthday is in a few min too. Im really responsible. I really want to go, can someone help me