for guys

Just because a girl may SEEM like she is not interested, it doesn't mean that she isn't. She may be playing hard to get, or she may not know what she wants yet...

If she is visiting you at your place, hanging out with you, spending the night with you (not doing anything, just spending the night) if you guys cuddle and flirt, then she is interested and it is OK to kiss her. don't ask for a kiss, take one. don't hesitate, and don't wait for her to make the first move. Remember: you are pursuing her! Don't be overly excited or too pushy.

be confident and make it clear that you want to kiss her, and then do it. I think it would be best if you guys were in a dimly lit room in case she's shy, and in a corner or closed of part of a room instead of standing in the middle of the room--so she won't feel so exposed. If you guys are on a bed, don't put all of your weight on her, being on top of her is fine, as long as she is not uncomfortable!!