Is it normal to like stranger sex

Okay so is it normal to want or trick your partner into sex with other people. Hetro relationship but could be any. Into light grey stuff, blindfolds and tied hands or feet nothing really hard. While blindfolded and hands tied, partner is performing oral and just playing when you become aware it's not them. Some how somewhere they switched people. Can't prove it but signs are there, smells, vocals, size, even when they talk voice seems to be slightly off from where you expect. The problem is you start getting upset but your body betrays you and it is so strange you like it but have no idea who it is or what's next. It last long enough you're not even sure it was just one or if both partner and stranger were involved or even more. We have safe words and I wanted to use it until I didn't. When the blindfold and ties came off partner was the only one around. But my question, is this semi normal. While in school I new identical twins that liked to switch I also new a couple guys that lived in the dorm and stories we're they would leave lights out and get up for a bathroom break and swap with a suit mate. Is it wierd I liked it and had multiple Os.