I'm from Paris. Today a girl looked at me several times; I think her parents or family were with her. We exchanged several eye contacts. I had a business meeting, I got off the train before her, and I couldn't approach her inside the carriage; given the crowd and the distance, it wasn't feasible.

Imagine she's without her parents. I wish she'd understand that I agree and get off at the same stop as me.

But aside from looking back at her, what else should I do? Wink, smile, wave like Duke Dennis?

Do you have any particular signs to tell a girl who's walking away on public transport that it's okay, that she should follow you?