Is it adultery or fornication... or, commitment vs. marriage

I got this link from Mark Oestreicher, president of Youth Specialties. At first, I found it simply laughable, and, with many others, I'm sure, felt sorry for the boyfriend for having to get rid of the parrot (note - not sorry for the loss of the girl). Then I waxed philosophical, and mentioned to Shari that, though Mark had titled his link, "adulterers beware" it wasn't really adultery, since they weren't really married. Then I asked her, "Why is anybody upset? Afterall, they weren't married, so there really wasn't a commitment, was there?"
Shari's statement was so true: "There is something inside of us that is made for that type of commitment, i.e. marriage, otherwise we wouldn't be so upset when even a pseudo-marriage is cheated on." Okay, that's not an exact quote, but that's the gist of it. I suppose if I'm going to use quote marks, I should get it right. So sue me.
Currently (5:48 PM PST) the Seahawks are ahead 17-6 over the Carolina Panthers. Go Hawks!