I really hate it when I look at someone and think, perfectly genuinely, something which I then realise is totally a chat-up line.
At the Calling tonight there was a girl who I kept looking at and wondering ‘now who does she remind me of?’. But, of course, if I'd gone up to her and asked ‘Excuse me, do I know you? I'm sure I recognise you from somewhere’, that would have been approximately the oldest chat-up line in the book, and I'd have had a very small chance of actually finding out what I wanted to know, compared to either getting slapped or (I suppose) accidentally pulling her :-)
Fortunately, I figured it out in the end and didn't have to bother her about it. Phew.