Are Louis Tomlinson and Danielle Campbell ALREADY on the brink of breaking up?

Louis Tomlinson and his girlfriend Danielle Campbell have only been together since December 2015, but already they've weathered Louis' love-child Freddie Reign being born to Briana Jungwirth and a whole HEAP of speculation about their future together.

And it sounds like they've done a pretty good job of keeping their relationship on track – until now.

Because the One Direction singer was pictured in Las Vegas recently partying with a load of women in bikinis, and Danielle is "furious" about it.

An insider tells heat that Louis turned up to the pool party during a business trip to Vegas – which is why he was there without Danielle.

"But when she saw him with all those girls in bikinis, she was furious," our mole says.

"She loves Louis but feels like sometimes all she does is work around him, and is expected to drop everything whenever he needs her, so this was a total slap in the face. Their relationship is on the rocks now."

Yikes.

Of course, it doesn't help that on top of all the Briana and Freddie drama, Louis and Dani are conducting their romance long-distance (Danielle lives in Atlanta when she films for her TV show The Originals, while Louis lives 2,200 miles away in LA).

Says another source: "Louis seems to blow hot and cold. One minute he’s doing everything he can to make her happy, but then he’ll act like a teenager and ignore her.

"He knows Danielle won’t hang around forever."

Sheesh.

It comes after Louis' babymama Briana sent a blazing message of defiance to her haters, after coming under fire for pretending baby Freddie was 'fake' (yes, really).

She took to Instagram to tell her followers how sick she was of the trolling attacks.

"This past year has been the best and worst of my life. I was blessed with the most amazing gift – a beautiful baby boy that I grew inside of me for 9 months," Briana wrote.

"On the other hand, I was scrutinized and harassed by thousands – which even included major media outlets whom all seemed to believe he wasn't real. I am beyond disgusted by it all.

"Being a new mom, I wanted to feel the joy and excitement and be able to share such a beautiful time of my life. For all of you who think doing this to myself and my innocent child is okay, you're highly mistaken.

"I also know that if it was said about you, you may not had the will power to hold back as much as I have."

Briana ended her rant by adding: "I will be strong enough to continue to embrace this journey, love my son endlessly and be kind to those who do not deserve it even if it's the last thing I'd like to do. Happy Mother's Day to myself. I'm proud to be Freddie's mommy."

Fair enough, really.

One Direction singers Harry Styles, Niall Horan, Liam Payne, Louis Tomlinson and Zayn Malik's faces switched around