My husband does this, I think it's him showing I'm his...
I might be very with wrong with m answer, but as I read read your question, the first thing thing that came to mind was "ownership"...
Actually ,He would be invading your personal space and should remove his hand forthwith.
It would be my initial move...<br />
after I caught her eye,I'd negotiate a discrete brush of her Nips<br />
before consummating the deal having our Carnal knowledge in private :)
It is the time when I need to go to toilet.
he's trying to nick your handbag, innit? :o