Why is sucking cock and the reward of cum so desirable?

[centillini]

For me it's same as eating a lady. Enjoying the act and bringing them pleasure. I actually get off more from the yelling and body shaking than the juice.

[momandson30]

some men love the reward of cum so much they will suck another guy against there will and take there cum. a random guy pulled my dick out and sucked it untill i cummed in his mouth.

[DLazguy]

And it's hot to come home with the taste of his cum still in your mouth and kiss her.

I've done that once. It was a rush. I want to get spit roasted and filled at both ends and then go home and fuck my wife. Have her rim me as I'm filled with cum.