From the front as well as from behind - well, absolutely flat woman. Only one advantage is obvious - well-designed orifices. And of course due to the flat buttocks it's very convenient to pull your partner in the anus, even without bending her over. And I don't see anything else interesting in this lady! The man is basically of age, so probably the determining parameter for him is the age of the woman and the possibility to work her anally!
Wow, they're all so hungry for sex. They really can't wait, the energy just goes out of them. With such a hard blowjob you might as well kill your girlfriend, you have to be careful with these guys. In two phalluses at once, that's what I understand guys in the shot, it's a double punch. They were really grinding all her holes, and the rate of grinding didn't drop until the end of the threesome.
Norm, although the girl herself is not very bright... the ass is not pumped up...