He also kissed her without her having a clue he was going to. The rest of the stuff about the feelings was fine. That, not so much.
To be fair, the only side of this story we've heard is from Flux, who is playing the role of jilted 3rd party in this particular story. And he heard it second hand.
Not saying it didn't happen exactly like that, and she could have been completely oblivious, but seems more likely that the guy just misread the situation a little. No one's ever been attracted to someone, and built it up just a LITTLE too much in their head. Told someone they liked them, or gone for a kiss when YOU thought you were having a 'moment', only to find out you might have fucked up a little?
Come on, guys! This wasn't some creepy stalker thing, or date rape, or whatever. Guy worked with a girl he was attracted to, read more into her attempts to be friendly, and made a move. After a couple minutes of hurt feelings, he tried to laugh it off a bit and backed off. Where's the f'ing problem here?
Know we gotta go all high drama, and talk about how he probably wanted to kill her and screw her (in that order), or puff out our chests and talk about beating his head in (all while pretending we're not treating women as helpless property that just can't be responsible for themselves), but I really just don't see the problem here, except for how Flux and a couple others seem to want to react to it.
The answer about what to do, however, is simple. If the guy stops - nothing. If not, and he starts doing it at work, she should report him for sexual harassment. That's really all that can be done.
Pretty much it, and what i said at the beginning. He fucked up and read too much into a pretty girl being friendly. If he drops it, that's it. If he pushes the line, he becomes a problem you have to TALK about, not resort to violence.
And the guy may not get Flux's respect, but his gf isn't his property, so the guy can make moves on whoever he wants. I mean, Flux even set his own standards for that! He said it was ok if he felt the girl's other relationship wasn't a good one. Doesn't take much more rationalization to feel that YOU could offer a better relationship than another guy, and to take a shot. Especially since, if you don't treat women as property, all you're offering her is an OPTION. If she feels the new guy is a better choice, good for him. Otherwise, she can just say no. It's not first-come, first-served, and no one has Dibs!