Rapper Tyga and his reality star girlfriend Kylie Jenner are rumored to have hit yet another rough spot in their relationship amid reports he may have cheated with Brazilian model Annalu Cardoso.

According to Us Weekly, the 26-year-old "Rack City" rapper is alleged to have been hooking up with Cardoso for months in 2015, at least part of their involvement coming at the same time he was also dating the "Keeping Up With the Kardashians" teenage star.

"Tyga is very careful and waits until Kylie is out of the country," a source added. "He would text [Cardoso] and ask how she was doing, casual conversation. Then he started asking her to send pics and to meet up. They hooked up a couple of times."

Word is the rapper first met Cardoso while on a video shoot. She ultimately appeared in an episode of his "Kingin' With Tyga" show.

The two are rumored to have known each other as far back as December 2014, or not long after he threw Jenner a 17th birthday party. Jenner and Tyga didn't formally go public with their relationship until much later, but it's no secret that they started dating long before officially announcing their romance.

Meanwhile, Tyga is rumored to have greatly played down his relationship with Jenner whenever he was around Cardoso, reportedly going as far as to act as if he was completely single.

"She never wanted to ask because he was acting like someone who didn't have a girlfriend, so she thought those were just rumors," a source added.

Tyga and Jenner briefly broke up earlier this year when she returned from a trip to Australia to be greeted by rumors of his infidelity. More recently, 14-year-old Molly O'Malia went public with allegations that the rapper had been sending her text messages that made her feel uncomfortable.