Circumcision, less is more
Circumcision is proof that sometimes less is more. His loss is my gain. Circumcision makes the man's penis less sensitive. That might lower the upper limit of how much sensation and enjoyment they can get from their penis, but at the same time, they'll last longer. The foreskin acts as a natural lubricant, gliding back and forth. This can be useful if the guy is rather large, but for the most part, the lack of a foreskin and the direct stimulation help to make him feel bigger. Scars can be sexy, especially when they undeniably mark that a penis made a sacrifice for my benefit. Lastly, a nice tight circumcision will make it a little harder for the guy to wank. That just forces him to give a little more attention to his partner to make sure she helps him get off. Circumcision is the perfect sexual equalizer. Men's bits are on the outside, easily accessible and easy to work with. Making it a tiny bit harder for men to get themselves off makes it just a tiny bit more likely they'll put in the effort to get their partners off. Circumcision, less for him, but more for his partner.