No. Just...if it's with somebody you care about, even if it's bad...It'll be alright.
Here are a couple of pointers...
If you cum right away, give it a few minutes. Then you'll be ready to get back in the saddle and be you'll be able to last a lot longer.
Find a bottom. That way you can get your penis touched, but do minimal in return. (And he might even be happy to help!)
Start with a lot of foreplay. Kiss. Massage. Investigate. The best sex is never (at least for me) about rushing to the finish line. I could spend hours exploring my partner and having him/her explore me. This will help you feel more at ease about the situation and loosen you up about the experience. It will also give you a better understanding of what feels good to your partner.
Along the same lines, know THYSELF...figure out what you like. You can do this by yourself, in your own home. Know where you like to be touched. Know what feels good and what doesn't. When the time comes, you can gently (or otherwise
) guide your lover to those sweet spots.
DON'T be drunk or high. This impairs your judgement. It can lead to STD's or worse-- you might be stuck having to make an awkward exit in the morning when you discover what you've woken up next to.
And finally, you always reserve the right to say no. Remember it. Use it. You can always find a new man. (Or discover that you like it rough.)