Let us compare this to another crime. So I sometimes keep my wallet on my desk, yes? If some rando comes by and helps themselves to some cash, that's a crime, right? But I'm totally okay with my partner doing that, and there's one or two other people I'd be okay with, too. It is
not a crime if one of those people takes the money out of my wallet. But, as it's my wallet, I get to decide who has that privilege.
Note, this depends on how I feel, as it's my wallet. Some people would never be okay with others taking money without asking. For me, at least, there's a small group of people I'd be okay with taking my money without asking.
Now, let us postulate that you think you are in that group with wallet access, but further postulate that you, in fact, are not. You think that I like you more than I actually like you. Even so, if you "confidently" grab money out of my wallet without asking, you are committing a crime, even if someone else performing the exact same action, someone I liked more, would not be committing a crime.
My point here is not to compare kisses to property, of course, but to point out that there are other places in criminal law where the perceptions of the victim and only the perceptions of the victim determine if it is a crime or not. In most of these cases, there's a strong default; by default, it's my wallet, and you can't take the money out without my say-so. By default, it's my body, and you can't touch it in a sexual way without my say so. Yes, you can make your assumptions as to your status, and if you are correct? that's cool. But you do so at your own risk. If you don't want to take that risk, you are free to ask.