I'm pretty sure this is what most of us hetero men are looking for in our Stag/Vixen relationships. The wife/GF has the say in who will be the other male in the MFM. There's some introductions, maybe drinks, you might lead with some fondling of your wife... but when it gets down to business, the wife and the other male are going at it with each other. You are the observer (filming possibly). You enjoy watching your wife being "naughty". The other male is about to cum and tells your wife. She holds his cock at the entrance of her pusy. He starts cummimg and she lets him shoot a little on her pussy lips. She wants to see it, she wants you to see it.... but then she puts the still shooting dick in her pussy and lets the guy pump half a load into her. It's a mental turn on for you to know your wife purposely put the sperm of another man into her married pussy. And she knows you'll be adding more cum in her. If you agree please comment. Or if I way off base