"Can I kiss you?" is legal advice, plain and simple. Because our legal system somehow thinks that no matter what a girl does, she is a victim, the hammer comes down even on things like kissing. To our courts, a girl does not enjoy kissing. Therefore, if you kissed her, it must have been 'unwelcome' and 'forced'. But what if you didn't physically force it? Why didn't she just stop you? Because you're a big scary man, and you intimidated her to the point that she 'felt too pressured' to not kiss you back.
In the US at least, any sexual act enjoyed with a woman who did not verbally express her consent is considered rape. By that logic most men I know are serial rapists (and if you read their 'statistics' they'll claim that a large portion of men indeed are rapists and that they simply don't realize that they are).