Sadly, Jon Hamm and Jennifer Westfeldt recently added themselves to the long list of star-studded relationships that crumbled this summer.
They announced their split on Monday, and their joint statement was predictably short but sweet, leaving out any of the messy details.
But that left many of us scratching our heads.
[ Video: Jon Hamm Poses As Bill Hader In A Trainwreck Interview ]
Why did their longtime love collapse after almost two DECADES together?!
Well, sources are saying that even though the two "definitely tried" to make it work and sort out their issues, there was one disagreement in particular that was just too big for the cute couple to ignore.
While the two were totally on the same page about not getting married, one insider explains that the Mad Men alum and the blonde beauty had two different opinions when it came to expanding their nontraditional family:
"There's always been a rift, because he wanted kids and she didn't."
Jennifer has opened up in the past about not wanting children, explaining that her life with Jon wasn't grounded enough to begin a family because she feels youngsters need the stability of a home that isn't so unconventional.
Another source added that Jon feels sorry about the split because his former flame was there for him through the good and the bad, saying:
"He felt guilty because Jennifer stood by him for so long when he dealt with his alcoholism. It's sad."
Our hearts are breaking because they couldn't work it out, but wanting kids is a pretty big priority for some people.
We hope that the split will allow them both to be truly happy.
[Image via Brian To/WENN.]
Tags: baby blabber, breakups, jennifer westfeldt, jon hamm, love line, mad men, sad sad