Well, it seems this big sis wasn't having any of it!
Koko took to Twitter on Monday with a very cryptic message about all the "sh*t", writing:
[Image via Instagram.]
We really hope this isn't true because if it is, that's absolutely awful.
And now, a source is telling Access Hollywood that the affair is much more twisted than your run-of-the-mill cheating scandal.
In fact, the insider claims that when the No Doubt singer gave birth to their youngest son, Apollo, last February, her then-husband left the hospital to hook up with Mindy Mann!
The confidante also alleges that the 50-year-old's mistress would bring his three kids to see him while he was on the road, and that they'd have sex on the tour bus after the children fell asleep.
Is it just a coincidence that she referenced the same month Apollo was born? Do U think Gavin left Gwen in the hospital while he slept with their nanny? SOUND OFF in the comments!
[Image via DJDM/WENN.]