Here's and idea: Give us a side B where the other 4 decided to switch partners as well. Triple swinging makes a manhood skyrocket. Oh don't forget a sequel or at least a epilogue where they continue their swinging orgy. ;)
...Well, I suppose when you take like, no time to even really check who you're night creeping on, mistakes are bound to be made?
That ending though, so it's become a kind of girlfriend swapping orgy party...?