"They have a very 'high school' relationship and argue and bicker all the time about stuff for no reason," a Jenner insider tells PEOPLE

By Melody Chiu and Nick Maslow
Updated January 23, 2016 11:30 AM
Credit: AKM-GSI (2)

Kylie Jenner and Tyga‘s connection is still there, but it’s strained, a source tells PEOPLE.

“They are together but aren’t on the best terms,” says the source.

The cause for the couple’s rough patch? Allegations that the rapper, 26, may have cheated on Jenner, 18, with Brazilian model Annalu Cardoso.

“They have a very ‘high school’ relationship and argue and bicker all the time about stuff for no reason, and that’s because Kylie doesn’t trust Tyga after all the reports came out about him cheating,” adds the source.

Following their last public outing together on Jan. 12, the couple have been spending more time apart. On Thursday, Tyga stepped out with model Val Mercado before Jenner partied with pals at The Nice Guy in West Hollywood.

Jenner spent her Friday night in with pal Jordyn Woods, sharing Instagram snaps showing the duo giggling while watercolor painting. “Best friend,” Jenner captioned one photo.

Earlier this month, a 14-year-old aspiring model and singer claimed Tyga sent her inappropriate messages. Tyga’s manager claimed the rapper was attempting to discuss a potential record deal and that the girl said she was 17.

Says the source of the latest allegations: “It’s made her really rough around the edges when it comes to him.”