Vecna13
This reminds me of how things were when I started solo masturbation. I would get so incredibly horny and felt absolutely driven to masturbate then, once I’d cum, the horniness would completely disappear and things would be back to “normal”, where normal was how things were before puberty, and I’d be thinking “Oh, why did I feel so driven to do that?”. Of course, I’d also be remembering how good the orgasm felt but the change in mental outlook from before cumming to after cumming is pretty big. Of course, as you do it more, you get used to the horny you (before orgasm) being every bit as much a part of who you now are as the not horny you (after orgasm) - that’s just what happens with puberty.
So I think what happenned with you and your friend was an extension of this. You got horny at a time when you happened to be together, you responded to that by jerking off together, then once you were no longer horny, it seems like a strange thing to have done.
Maybe you just need to talk this through. Acklowledge that horniness that demands to be dealt with is something that you’re both familiar with and that it can alter your outlook until after you’ve cum and are no longer horny. Acknowledge that cumming to deal with being horny, and to enjoy it, is completely normal and there is nothing wrong with that. Then decide if it meant any more than that. There are lots of things that we do in life that are fun, and many of them we do with friends, yet sexual stuff seems to be the odd one out in that we are encouraged to see that as something more than just doing something you enjoy with someone else who also enjoys it.
Maybe, as a result of that discussion, you may decide not to do it again. Or maybe you’ll decide it is some harmless fun and decide you will do it again. Either way, though, the most important thing is that you are on the same page.