What's his problem!?

So this whole play seems to be situated around Laura and how she needs to find a husband. Even thought the two have their differences, Amanda and Tom work together to try and make this happen. Once Amanda realizes that Tom has invited Jim to have dinner with them so he can meet Laura, Amanda gets very excited and goes out of her way to fix up the apartment and make a good dinner. Well, Jim goes and has some alone time with Laura in which the two then seem to become intimate. For a moment, I really thought that the whole pairing up idea was going to work and Jim would want a relationship with her. So they then kiss and then.......he tells her how he has a girlfriend he is going to marry!! What the hell dude! Talk about messin' with her mind man! I mean, Jim did give her great advice and maybe was actually a positive influence on Laura, but he did not help the relationship between Tom and Amanda. In my opinion, he was actually the catalyst of Tom leaving for adventure. If he had only told people that he was engaged, then Tom would have never invited him and maybe someone else could have been invited by Tom. All in all.....I did not like Jim (and he thinks he is too awesome)