I think the appropriate time as a Christian to kiss is after when you say "I do."

But more of a secular way of looking at it, if you look at her lips a few times like 3 or 4, it's like giving a signal to her telling that you want to kiss her. It's all up to you to break that first move. If you're still not sure, scoot up to her side and if she hasn't scooted away from you, brush/stroke her hair a few times and smell her neck slowly. If she hasn't scooted away from that, then she's probably ok with you kissing her. Ok, this is sad and I fear that I'll lead someone astray. I'm heading over to the repentance corner now!!!