Never ask to kiss a girl, just do it. Your first kiss should arise out of the situation because you both want it. Its something you feel, not something you sign a contract on.

Is it OK to kiss without asking?

This is not true. If you ask someone permission for a kiss and they want to kiss you, theyre not going to reject you because you asked first, even if they didnt think it was necessary for you to ask. Sure, theres also a chance that theyll say no, and that might be embarrassing.