Foursome while in a relationship

so like less than 48 hrs ago I had a foursome with my boyfriend and his guy friend and some girl we had all just met that night.

I was reluctant at first, it had always been something I had cross my mind over the years but never seriously thought about it and never when in a relationship. My partner brought it up and pursued it, after asking me obviously. Was very much an in the moment thing.

So anyway, we all got back to our motel and he just didn’t have any hesitation like he was basically like to the other girl, bend over and bam, didn’t really consider helping me ease into it. Like idk I literally feel sick thinking about it now because he was so not hesitant.

It was actually fucked up seeing him with someone else and not even considering how I was feeling right next to him. I only say that because my one rule before we started which he agreed to was to help me feel comfortable and to not just leave me in it alone, which I feel is exactly what he did. Like it got to the end of it and he had barely seen or touched me the whole time.

It’s just put me right off and I honestly don’t know that I can get passed it. I’m an over thinker and it’s just really upsetting me and making me think that if he can do it that easily then maybe it was just him wanting to fuck someone else and have it not technically be cheating.

What is everyone’s thoughts or experiences with this?