One love triangle that is nearly impossible to keep up with is Rob Kardashian and Blac Chyna‘s.

The model and business owner, 28, took to Instagram to wish her ex, 30, a happy birthday — which fans found odd considering they are currently battling over custody and child support when it comes to their four-month-old daughter, Dream Kardashian.

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“Happy Birthday @robkardashian,” she captioned the image.

https://www.instagram.com/p/BRv8gmMBfyo/

The pair recently split again and Chyna is not only gunning for full custody of their baby — she threatened to expose the sock mogul’s dirtiest secrets if he doesn’t pay what she requests in child support.

“She has evidence of him partying around [their baby, Dream], calling her names, and grappling her when they’ve gotten into fights. Chyna’s got the proof!” a source told Radar Online. “She has told him he cannot be alone with the baby. She doesn’t trust him.”

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However, Rob is also gunning for custody — and In Touch exclusively revealed that he even has his momager, Kris Jenner, on his side.

“Rob and Chyna have split for good, and now Rob wants full custody of Dream,” said a source. “Kris is 100 percent behind him. She doesn’t want him paying child support.”

While we haven’t heard of Rob moving on from their most recent split as of yet, it’s been rumored that Chy could get back with her ex-fiancé and King Cairo‘s dad, Tyga — now that he allegedly split from Rob’s sister Kylie Jenner.

“Blac Chyna could absolutely get back together with Tyga. Returning to the father of her first child would be highly unlikely, but Blac does have a soft spot for Tyga,” a source previously revealed.

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“Despite all of his shortcomings, Blac feels Tyga is a generous person with a heart of gold. She fell in love with him once before and, if the timing were right, she could totally see herself giving it another shot with Tyga.”

Scroll through the gallery to relive Chyro’s cutest moments!