Help Me!!!

Hey guys, i need some advice.. so, i’ve been in a relationship with my boyfriend for 3 years now, we’re actually leaving for a cruise together with my family on the 14th (our 3 year anniversary).. i wanna have a good time and enjoy it with him, but.. theres a slight problem.. i met a guy in my History class and we instantly clicked and became good friends. we’ve had a snap streak for over 2 months now and today he came and helped me when my car broke down... i really like this guy and want to see where things go with him but i also don’t want to hurt my boyfriend. i’m also scared that if i do break up with my boyfriend to see where things lead with this guy, but what if my boyfriend wouldn’t take me back if i went back to him.. i know that seems selfish but ... HELPP