Really hate it when guys do this. Why bother sucking cock if you're not gonna finish the man off properly? And by "properly", I mean you let him cum in your mouth and not ruin his orgasm by pulling away and then using your hand. What you do with his load afterward (spit or swallow) is up to you. We don't have to SEE his load...we can tell when a man cums.
This is exactly my mantra and won't deviate from the course. If I care to share my married penis with anyone, especially another man, I want to know my semen has been consumed and is inside of them.