I don't think your question is inappropriate, but I think some people might be disturbed by the answer I'm going to give from my own experience: which is that when you think about someone, effectively you are calling them, calling their attention to you. So if you are thinking about someone in an erotic way, you are calling them with your feelings/emotions/mental pictures. It is possible for the person receiving to simply block these out as unacceptable (they are not attracted or they feel uncomfortable about it for some other reason). If they are attracted, they may simply join in. If you are doing this yourself, I say this: when the fantasy takes on a "life of its own", rather than you imagining what you like, that's when the other person is joining in. It is all very innocent, really. There's nothing wrong with sharing pleasure like this.
If you are experiencing a creepy feeling that someone is reaching for you and you don't want to join in, then don't. It's that simple. They are very unlikely to be mentally strong enough to do you harm by trying to insist, but if that happens, pray and ask your guardian angel to intervene.
I'm not sure most people are ready to realise that they are not alone in their own heads, so I hope I haven't freaked anybody out!
