It's an interesting fantasy to paint such a fat ass green! Ladies with such an ass are especially good in the crawl position, a boner is assured. Except you have to have a decent length tool. If you don't have one, I recommend laying the lady on her back and fucking her with your hands on her thighs pressed up against her belly. Otherwise you can't get the dick in deep.
Men, as a rule, determine the course of a gangbang, and here three ladies, with a third and above the size, just pounce on the guys' dicks! I guess that's what they call it "