Kendall Jenner and Harry Styles are reportedly bound for a split. The model is said to be furious at the One Direction singer for two-timing her with fashion stylist Pandora Lennard. Jenner showed she's unhappy with her boyfriend's behavior during common friend Jeff Azoff's birthday party over the weekend, per The Sun.

According to the news outlet, Jenner left the birthday bash held at the Troubadour in West Hollywood, California, just in time when Styles was giving a speech on stage. The Estee Lauder model reportedly made a dash outside around 2 a.m. in the middle of Styles' comedy "roast" of the birthday celebrant.

"It doesn't look good for Kendall and Harry. She cancelled a lucrative modelling gig the other side of the world to be at Jeff's birthday. There was no reason for Kendall to leave as they're good family friends so would have been expected to stay until the end like Harry," a source told The Sun.

The source added that Jenner only stayed for an hour at the party. She reportedly didn't look happy when she arrived at the venue nor did she looked happy when she left the party. The Sun shared a photo of Jenner in a pensive mood as she left the venue with her mother Kris Jenner in tow.

The Victoria's Secret model reportedly left the party following reports that Styles two-timed her with Lennard. The 27-year-old stylist was spotted outside of the singer's Hampstead home one Sunday. It's believed she spent the night over at Styles' place. She was spotted looking a little bleary-eyed when she left his pad before noon. The Sun posted a photo of Lennard leaving Styles' house on its previous report.

However, Lennard reportedly denied to comment on her rumored romance with Styles. Sources who know the pair claimed Styles and Lennard had always been friends. However, it was believed they were attracted to each other.

The said insiders likewise told The Sun in a previous report that they never thought something romantic would happen between Styles and Lennard because of Jenner. After all, the 20-year-old Jenner and the One Direction singer made it known in December that they were officially a couple.

Whether Styles' rumored fling with Lennard will soil his relationship with Jenner is still uncertain. However, another source said the couple will not let anything, even the distance, ruin their relationship. Jenner and Styles have reportedly vowed to keep in contact with each other through Skype and text messaging.