When having sex missionary style, when he puts the leg up so my knee is bent up to my chest... is he doing this so it feels better for him, or for me?
If memory serves me right, the kama sutra said that position can help the man penetrate deeper and may be more pleasurable for both people.
Edit: It really depends on the people.
i dunno, my girl loves that stuff, so i am guessing for you. cause she goes wild when i do things like that!