Megan Fox figures to have an interesting, and potentially challenging, family dynamic now that she's pregnant with Machine Gun Kelly's baby ... because things sound icy between MGK and Megan's ex-husband, Brian Austin Green.
Sources familiar with the situation tell TMZ … Brian and MGK have no relationship whatsoever, which could lead to rough waters when it comes to co-parenting.
Megan has 3 kids with Brian and our sources feel MGK hasn't been involved enough in the sons' lives ... or even made an effort to be a father figure to them.
MGK and Megan went public with their romance in 2020 -- shortly after her split from Brian -- and we're told they all crossed paths in 2022 when MGK attended a school event for one of Megan and Brian's kids.
Folks who were at the event say Brian wanted to break the ice at the event and forge a cordial co-parenting relationship with MGK ... so he approached MGK and introduced himself, with MGK offering nothing more than an unenthused "What up."
We're told MGK didn't even make eye contact with Brian ... and MGK made it clear he didn't care to have a relationship with Megan's ex.
Our sources say MGK and Brian haven't spoken or seen each other since.
That's worth monitoring because the family dynamics are changing now that Megan and MGK are expecting their first child together.
Our sources say Brian would like MGK to have a better relationship with Megan's sons -- but as far as the 2 men having a relationship, we're told "that ship has sailed."
Brian's moved on romantically too ... he's engaged to Sharna Burgess and they have a 2-year-old son together ... and our sources say Sharna has a great relationship with Brian's boys and Megan.
We're told Sharna made it a point to introduce herself to Megan, and they've exchanged numbers ... with Brian and Megan's kids even referring to Sharna as "mom" because she's so involved in their lives.
In other words, the exact opposite of Brian and MGK.