A girl I dated would often pick up Cosmo for the fashion and while I often had to wait for her to get ready, I would flip through the sex tips. Literally in every issue I ever picked up of Cosmo, there was one tip that basically said "Next time, without warning, right as he's about to finish, flick his balls." Sometimes it'd say lightly or something. I remember one time they were focusing on using objects from around the room. This particular tip told girls to take an elastic hair tie and wrap it around his dick so he can't finish and then repeatedly flick him in the balls as you give him a rough handjob.
This is why I have a sneaking suspicion Cosmo is actually trying to prevent teen pregnancy with their sex tips. Once you have a girl abuse your genitals, you don't really want to ever get naked near her again.