The above post is incorrect.
Spermatozoa can 'live' outside of the body for up-to 2 hours.
Although the chance of your partner conceiving IS very slim, it can't be ruled out willy nilly.
It has happened before (JD on scrubs for example lol)
If it worries you that much though, use a condom like a wet wipe, as these have spermicide covered on 'em
I wouldn't worry too much though,... Just be more careful in future