I am usually a slow cummer because as someone said above, I enjoy it too much and don't want to end. If I feel myself getting close to orgasm/ejaculation, I instinctively back off. So I usually go 30 to 45 minutes. If it's just my wife and me, she'll cum twice or thrice in that time, but if we're in a real hurry I can do it in 5 minutes. In a swinging situation I will go as long as my partner wants, maybe 15 minutes, an orgasm, then stop, eat her out if she likes, then move on to another woman for another 15 minutes or so and cum in her. There was one time, however, I kept going and didn't cum until I finished with the 4th woman.