cambriadude
LPSG Legend
This is from the Swingers Dictionary of terminology in the USA and Canada.MMF threesome doesn't imply the men are going to have sex with each other, just that two men will be having sex with a woman at the same time.
MMF would be two men getting it on with a female, while also tending sexually to one another. The same is true for FFM—two females sharing one man while being intimate and sexual with each other, too. These types of threesomes are popular with bisexual swingers and those seeking to expand their boundaries or double their fun in playtime. In a MFM the men would not be intimate or sexual with each other.