Bring toys into the bedroom and make sure that you talk to your partner. This can be a very touchy subject with men because it could be that he thinks he is getting you off. Make sure that you talk about it with him, but not in a way that makes him think that you're not enjoying it and that's why it needs to change.
You might talk with him about slowing things down. Play with him some and let him play with you. Try some mutual masturbation. You can also work yourself up for a short time. That will make it easier for you to orgasm and get him excited. If he's never seen you masturbate, you're going to be surprised at how excited it makes him. If that doesn't work, you can always look into delay creams or sprays, but only if he's interested in it and only after you two have talked and you've tried other things. If you're not careful, it can turn into a difficult conversation.