While some are raising the "marriage card" to absolve the people in this situation of any wrong-doing, please keep in mind that in some countries, people who live together for a certain length of time (usually it is between 6 months - 2 years) ARE BOUND BY LAW. Hence, when/if they split up, legal issues apply. For e.g., f one half of the couple was "wronged" in some way, he/she has LEGAL RIGHTS. Also, they are entitled to "half" of the other person's earnings etc. In short, legally, this break-up could go to court, just like a marriage splitting up could.
So if you are making a "legal" argument to call this situation a "non-issue," it doesn't factually hold.
If you are making a religious argument, that's different, but even so, moral issues apply whether married or not married, religious or not religious, as morals/ethics aren't bound by spirituality. Therefore, I assume if one has had the same partner for, let's say, 3 years, if he or she cheated, I can assume the other person would think it was "morally" wrong.
All that said, however, I do think "sweetcandy" brings up a valid point: clearly, Brad, Jen and Angie garner more public interest/press than Jen, Justine and Heidi, given that some people would say "who?" regarding the latter two involved in this recent triangle.
Further, the Brad-Jen-Angie triangle revolved around a film, "Mr. and Mrs. Smith," which was just released right around when the story broke and which was loaded with sexual chemistry. Angelina had the "bad girl" image going as well, so that fed into the hype.
The Justine-Jen-Heidi triangle seems to have happened much more "behind the scenes".
But - imo - it does utterly re-write the cliche narrative that Jen is "America's Sweetheart" and "The Wronged Woman" of Hollywood. Frankly I find this alteration in her image refreshing!! It allows Jen to finally get those "labels" and "cliches" off her back and be her own person, kind of how Angelina has been able to change her image through her Oscar nominations, Charity work and, of course, motherhood and family life.
Who wants to be stereotyped!?
This might be where one begins to wonder about PR! Especially given that Jen's forthcoming role as a "sexy corrupt dentist" plays right into this re-writing of her image as "spurned sweetheart". But of course, this could also definitely be pure coincidence.
Nonetheless, it is the potential image shift that makes the story interesting to me.