Quote Originally Posted by denuseri View Post
Fingers and tongues come to mind.
I had a boyfriend once who while giving oral would cum (without me touching him) every time. Although I guess this is rare.

As for the OP, does she specifically want to have intercourse, or does she just want to get off without you getting off? If that's the case, then I'd agree with denuseri to use your fingers and tongue, or whatever else your Mistress would want you to use.

If she specifically wants intercourse, you may have trouble controlling yourself. If it's ok with your Mistress, you may want to masturbate before a session with her, or perhaps even spend time by yourself working yourself up and stopping, so that you can better control your ejaculations. If you warn her when you feel close, she may be able to do something to stop it, either stopping and taking a moment, or inflicting pain (if that would stop it).