Depends on the situation. Sometimes I don't want to cum... maybe I just started my night and I want to suck off a lot more guys - if I cum, then i'm not really interested anymore (it's the straightest thing about me). Cumming is not the goal for me. I like when I run into a guy who has that as a goal because it means I can really go to town on his dick.
Usually when I cum it's because I've sucked so much dick that I just cum hands free, or I'm in a more Top mood and doing the fucking. Or, when I'm having full contact, intimate sex with someone who I know well and share more than just sex.
Sometimes a perfectly good encounter winds up being spoiled in a futile but relentless quest to break through a plateau and cum; it turns from play into a chore.
Even during a casual hook-up, I'm always attuned to where he is at, physically, mentally, emotionally, sexually. I don't ever just bust a nut without discussing it with whomever it is I'm playing with, even if it's just a simple question. That's selfish egosex, not even a sportfuck and definitely not the way I roll.
As a non-versatile top who can sometimes take edging to an extreme, play is the journey, not necessarily the destination; after 7-8 hours of assorted fun and games, it's hardly unusual for either my partner or me to simply find a nice spot to break, relax and cool down. Actual ejaculation needn't be part of the equation, especially when it becomes something of a
mystery achievement