'In the best of the short con heart-stoppers, George dressed up in clothes he called 'a little past sharp' and then toured some Boston bars he knew about. These weren't gay bars and they weren't straight bars. George called them 'gray bars'. And the mark always picked George up. George never had to make a move.'
I bolded the phrases I need help with, especially the second one, as I have no idea what 'the mark' means in that case, hm. Thanks for any suggestions :)