I think I can safely say I have a frenelum. I can say one thing for sure. That line under my dick is hella sensitive. I can do better jacking off by running that part softly with my hand. It's more sensitive than my head. Which it too is pretty damned sensitive. I've heard some women say that cut and uncut guys fuck differently. As in it guys are in and out and uncut guy bump and grind due to more sensitive heads and the women prefer the bump and grind. Well, I've always been a bump and grind guy because I live watching them squirm and have multiple orgasms. I was cut a couple days after birth. Atlert the doc left that part nice and sensitive.