Getting old has done the opposite for me, as time progress, I start to cum sooner rather than later. But I think it's the tight schedule and work culture that needs me to finish everything fast.
If I want to really last, I'll withdraw, unwrap, cum all over without touching. Psychologically, I didn't hit the biological target, and for some reason, I stay hard and want to go for another shot. Second round last much longer, and if I withdraw again, I can keep going for thirds ... But it's just an exercise the third round.