Yes I've done this, but it was several years before I met a sex worker, and we used condoms. But it was neither fetish nor fantasy, but more like opportunity. During my college years there were a few gangbangs, there would be 5 or 6 of us with 2 girls. Poor girls were just trying to reach orgasm and we were pretty much one shot wonders.
My wife caught me wearing ladies underwear and threatened to leave me.
So I packed up all her clothes
And left.
Appreciate the input brother but it's not really sloppy seconds with a condom! It's all about sliding in after another guy cums and mixing your cum with his. Although in your situation you were right to do it with protection, I'd only do it with somone I knew was clean.