When you and your wife decide on her first MFM (Stag/Vixen) night, it'll usually start out something like this. Some or all of the clothes come off, there is some cuddling. As her husband you sorta take the lead to let her know it's 'okay'. The other male usually follows up with similar moves. Your wife gets more comfortable, might be some kissing, but eventually her tits become the focal point. You suck on your wife's tits which gives the other male the okay to do the same. Your wife starts to think, "Alright this is okay, it's the same thing I do with my husband it's just that there's two of them".