The site reports Tyga and Annalu met during one of his video shoots, and she also appeared on an episode of his MTV2 show, "Kingin' with Tyga."
Tyga and Kylie's relationship started being rumored about in July 2014, but their status wasn't official until the reality star turned 18 the following summer. According to a source, Tyga started texting Annalu around December 2014.
"He would text her and ask how she was doing, casual conversation. Then he started asking her to send pics and to meet up," another source told Us.
"They hooked up a couple of times, but for the most part they would just hang out," the insider added.
Tyga also allegedly introduced Annalu to some of his friends.
"She and Tyga wouldn't be extremely affectionate in front of them, but she could tell his friends all knew that they were something," the source explained. "If someone else was sitting next to Tyga, they'd move so she could sit next to him."
Tyga and Annalu's relationship reportedly dwindled, though, after he was worried that their fling might be publicized.
"He used to find a way to see her, and that stopped," a source told Us. "They never officially stopped seeing each other, but she's stopped talking to him."
Kylie and Tyga's relationship hit troubled waters in November 2015, when the couple briefly split up. Shortly after, the reality star told Ellen DeGeneres he was her best friend and they were still together.
Tyga's alleged wandering eye came into question regarding a different instance earlier in the week. During a press conference on Jan. 4, a 14-year-old singer claimed the rapper made advancements at her and sent her "uncomfortable" messages.
His rep refuted the accusations, claiming Tyga was just offering the teen a job opportunity at his Last Kings Records music label.
We'll have to wait and see how Kylie reacts to the cheating allegations, but it sounds like she won't be getting much support from her family. A source exclusively told RadarOnline that "her family is over him."