This person could be a co-worker, family, or something else.  But, anyway, he's certainly a snake-in-the-grass. So what is his problem?  Well, in one case I know of, the jealous man is a total failure while the husband is a success.  So in that case, to get revenge and to satisfy lust - the rival might even try to bed the wife.

Well, this does seem like a freak story,  but I've seen it before, and I'd be on the lookout!

Oh of course, but I think it's important to note that both men and women are snakes.

Luckily for me, my boyfriend lets me know whenever something like this happens, or a woman is hitting on him or says weird, creepy things.

I do sometimes ask myself if I really want to know though, what you don't know, doesn't hurt, right?

I think all couples go through it though, if your woman is a decent looking lady, then tell her, and make her aware that's probably why other guys are interested. Remember, these dudes may be chatting her up, but she's going back to your bed every night!

What the OP is describing is insane and flat out dumb!    However, though, human nature is so on the edge, that I can very well see it happening!  I mean, jealousy, lust, and a feeling of being belittled (normally by the middle-class or rich) can certainly make a case for revenge (from the humiliation).