Let the mudslinging begin!

Kylie Jenner and Tyga have been broken up for a month now, but we're just starting to learn the real reasons behind their less-than-friendly split. Apparently, the teenage reality star hired a private detective to follow her rapper ex for months, only to discover he was cheating left and right behind her back!

"She buried her head in the sand and refused to believe he was unfaithful most of the time, and the times she busted him he always managed to convince her he never actually slept with anyone. [The hired detective] followed Tyga for months and gathered irrefutable evidence of his cheating. Kylie now believes that Tyga slept with at least 100 other girls while she was dating him, and she’s having a very hard time with it," a source dished to Radar.

Now, Ky has to worry about STD's!

"Everyone’s urging her to get herself tested, but she’s too frightened right now, even though eventually she will have to face getting answers," the source added.

T-Raww is trying to flip the script, though, and make it seem like the Lip Kit mogul was the unfaithful one!

"Tyga is telling people that Kylie was the one cheating! Tyga flipped out on Kylie after he found out that she was hooking up with PartyNextDoor. He accused her of cheating on him while they were still together," another insider revealed. "Kylie now has Tyga blocked and unfriended pretty much everywhere. She even told the guards at her community in Calabasas to never let Tyga in for any reason!” they added.

Kris Jenner's youngest daughter is never gonna take him back, but he's got other options! He could always call that 14-year-old girl he was harassing on Instagram or his transsexual mistress Mia Isabella.

What an epic saga!