Look, when you have sex with someone, whether it's a one night stand or a long-term relationship, you need to take the other person's wellbeing into consideration - hell, that's what makes sex so nice, it's two (or more) people having a good time together - otherwise you're just using their body, and it's not on, you may as well use your hand if the only person's orgasm you care about is your own. I've had one boyfriend who didn't give a toss about my needs during sex - he didn't stay a boyfriend for long.