Okay so this is my first time posting, but I hope you guys can help me out!

Here’s the situation: I have an amazing boyfriend, treats me well, been together for about 8 months, and things are great. I am a freshman in college and have a friend Nick who is still in high school, a senior, who just got dumped and needs a date to prom! He hinted at asking me and I asked my boyfriend, who met Nick before and is cool with him, if he’d be okay if I went to prom with Nick just as friends of course. Now, I have never given my boyfriend a reason to mistrust me. I’m super loyal and even show him off! He immediately got angry at me when I asked him and said I completely disrespected him and our whole relationship and that he doesn’t know what to say to me... (which really really hurts because I feel like I messed up, but when I personally think about it, it’s a matter of trust!) I believe it’s okay for me to go to prom with Nick, wear a conservative dress, no slow dancing, and have a great time seeing friends and teachers at my old high school! My boyfriend is ignoring me which has never happened.... what do you guys think?