There's nothing wrong. The more erotic the sex and the more sexy the woman, the faster a guy will finish. If anything, it means he finds sex with you great.
That being said, there are some things you two can try to help him last longer.
1. There's some desensitizing cream he can rub on his penis that will lower the sensation of sex and maybe help him last longer.
2. Condoms can do this too...the thicker the better. Any condom labeled Extra Strength tends to be thicker. Stay away from the ones that say they are thin or feel like you aren't wearing anything.
3. He can get to use to his feelings and when he feels that he's getting close, he can pull out and stimulate you with his finger or orally until that feeling subsides, and then he can plunge right back in. This can be done repeatedly.
And lastly, there's a wonderful drug called Dapoxetine that treats this. Unfortunately, it's not approved in the USA yet. I'm normally a 2 or 3 minute guy during intercourse, but a 30 mg dose of this makes me more of an 8 to 10 minute guy. A 60 mg dose turns me into a 45 minute guy.
I've ordered it from overseas on the site I've linked to. You can trust it or not, but I've had great success with this site. And if you do order from them, you have to give them a real phone number, because they will call right away to verbally confirm the order.
If by chance you mean he wilts during sex before climaxing, I again recommend using the site I gave you.