Ariana Grande & Big Sean Relationship News Update 2015: 'IDFWU' Rapper Reportedly Caught Cheating; Did Couple Reunite?

Ariana Grande reportedly caught rapper boyfriend Big Sean cheating recently -- did they really break up?

"During the last visit they had together, right before Christmas, Ariana reached for Sean's phone and he about jumped out of his seat," a source revealed to Star. "She questioned why he was so jumpy and insisted on seeing his phone."

The "Break Free" singer apparently found a bunch of texts and photos received from other women on the G.O.O.D. Music artist's device.

"He tried to play it off and swears he hasn't hooked up with anyone since they became official, but Ariana was devastated," the source said. "She couldn't believe the sort of things she saw them talking about to him!"

The source added Grande immediately dumped Big Sean: "She refuses to return his calls. She feels completely violated and has lost all trust in him. His grandma passed away a few days later and she hasn't even called to check up on him. They're done!"

Similarly, MediaTakeOut.com reported the "I Don't F*ck With You" rapper was having a "sexting relationship" with a popular Instagram model.

"He never slept with her, but she was down -- when he came to Miami next," a friend of the Internet model said.

"Ariana Grande got into his phone somehow and saw all the messages," the friend added. "Ariana actually called and started talking sh*t. It was kind of funny to us."

However, reps for the "Love Me Harder" crooner insisted the recent claims are "absolutely not true" and that the couple is still together (via Daily Mail).

Ariana Grande also cleared up the split rumors this weekend, as she took to her Instagram account to share several PDA photos taken with her lover during their trip in Lake Tahoe:

Big Sean did the same: