Girls rubbing on the frenulum, preferably with cumshot and where you can see the girl. So hard to find stuff like this.
http://www.hclips.com/videos/rubbing-the-sensitive-part-of-my-dick-until-i-cum/?promo=11914
examples
http://www.hclips.com/videos/girl-spits-on-her-bf-s-cock-and-rubs-the-sensitive-spot-until-cumshot/?promo=11914
http://xhamster.com/movies/1966920/punheta_com_dedinho.html