To the virgin's defense (lol jk) maybe he meant that he wasn't expecting it to sooo floppy, you know, even though you seen it in videos very few have seen it when hitting it from behind or when riding, the kinda booty waves it makes.
I had a 5'4" with a 64in donk that decided to lose weight, she went all the way to 56in fast (mind you I was measuring that shit often) and that shit was just too loose, too jiggly. Before it was stiff and hard like a mofo (not true that only body builders have them look at Big Lizz for example before the weight loss) so much that I wasn't enjoying fucking her anymore and had to split