Personally, I would probably end the relationship before it got too far. Because, as much as people want to hold on to their 'no kissing' thing, as you get closer to each other in the relationship, you tend to get more personal and have the possibility for intimacy.
So this leaves you with two options:
-The guy agrees to wait, despite both of you wanting to really get intimate by kissing, etc. This will eventually put strain on the relationship, IMO.
- The girl gives in and kisses the guy, and then there is the guilt of breaking your own moral standards.
I would personally just avoid that situation altogether by dating someone who is willing to kiss or whatever, but not break the sex threshold.