i really did it this time

my partner and i have been together for a few years now but we've never done anything too out there sexually. last week i was feeling kinda adventurous though, i dont know if you get that vibe sometimes too? so i suggested something that i had always wanted to try with someone who really knew how to make me feel good in bed. i told her about this fantasy where another guy would be involved and how it would feel knowing she was getting some from a different person at the same time as us. she kinda looked shocked at first but then we talked more about it, and she ended up saying yes if it meant so much to me. i had met this other guy before through a mutual friend, he's actually in his mid thirties which is a good 10 years older than both of us. i never really clicked with him or anything but after hearing about my fantasy and seeing how eager i was to explore it, we ended up setting something up at our place one night when my partner would be working late. so here's the thing, we did this thing where he came over dressed in all black, blindfolded me, tied me down to the bed with these really tight leather straps, and let her watch him slowly tease me while i was helpless. it was so intense feeling all those sensations on my body, knowing she could see everything that happened and i couldn't even look back at what he was doing. then when we switched positions for her turn to be tied up, this guy had these long metal rods with hooks on one end that he used to hook onto parts of her body like pulling her nipples or sliding it between her legs. she screamed the whole time but i could tell it wasn't from pain, just total release and pleasure. in the end we all three got together for a threesome, me still blindfolded and the other guy directing us in ways that made everything feel so intimate and dirty at once. afterwards my partner didn't say much but she was smiling and looked happy with what happened. i know this is gonna sound insane to some people but honestly i don't regret any of it and would probably do something like this again if we could keep our dynamic going. so...am i the asshole here? did i cross a line even if everything felt consensual between us all?