My partner's tight vagina causes my condom to slip during a threesome with my best friend

I've been with my girlfriend for years and things have gotten a bit predictable. I've been fantasizing about bringing another guy into the mix, preferably my best friend. One night, we decided to spice things up with a threesome. My partner is super tight down there, almost to a fault. As we were getting into the action, her tight vagina kept slipping the condom off my friend's manhood. It was a bit of a hiccup, but we rolled with it. I took over, hoping her tightness wouldn't affect me. But suddenly, my condom slipped too! We were both fucking her bareback, unprotected. The thrill of the risk made the experience even more intense. We all came together, our bodies entwined in a steamy threesome. No condom, just pure, raw passion.