When is it appropriate to give your yummies out?

I know Christians are suppose to keep thier yummies locked up tighter than a can of tomatoes with only a piece of dental floss to open them but in 2008 no one is going to give my parents 8 head of cattle and a good goat for a dowry so my question is on the dating scene(which I havn't been on in a long time) I have met a realy nice guy and don't want to make him turn blue in the face (Or anywhere else) but how long can I or should I put off giving out my yummies? We live in such a microwave world but there are too many std's out there and seems to be not just a pre-marital thing now but a well, let me see if I even want to date you thing, now.