There are two possibilities here: He's just as much of a tedious coward (ie. an AFC) as she is, and so we end up with a situation where both parties allow themselves to be ruled by a fear of rejection. This mean that she gives him "hints" - signals that are supposed to show an interest but always allow her to deny to her friends and peers that she's been rejected. This is for some reason important to a lot of women. They then have the cheek to get frustrated with the lack of the man's advances. The man, in turn, is arrogant enough to believe that his peer group holds him in such esteem that being rejected by her would be so disastrous for his reputation, and is unrealistic to believe that always tip-toeing around the edges won't have him classed as a pansy or AFC by the people observing this. At some level he has a better understanding of the situation, so he rationalises his COMPLETE INACTION with the fact that some women think that any advance is sexual harrasment and similar american rubbish.

More likely is that he's not actually interested in her and so pretends not to notice these "hints" - women are rarely excited by passive and unexciting men. This can result in the same kind of situation, as he indulges these "hints" but doesn't act on them so as not to give her "the wrong idea", despite the fact that that's exactly what he's doing.

People, if you can identify with this situation, PLEASE stop being so passive. I'm not advising you to do this for your own sake but for the sake of the rest of us, who are sick and tired of hearing about this self indulgent mental anguish again - we've all heard it before and unfortunately probably will again, and I can assure you that the situation is probably not as interesting, unique or disastrous as you'd like to think. I'm surprised so many people have the patience for it.