Bradley Cooper and Irina Shayk have reportedly split.
The pair started dating in April 2015, and appeared to be happier than ever with reports they were even considering moving in together.
But it has now been claimed that Bradley, 41, decided to end his relationship with 30-year-old Irina following a series of clashes between her and his mother Gloria over the festive period.
A source said: "Irina thought things were going brilliantly with Bradley and is very upset they ended this way. The pair had been getting on really well, but things went south over the Christmas period.
"They spent Christmas together in Los Angeles but arguments started, mainly centering around the fact Irina and Bradley's mum weren't getting on very well."
According to the insider, Irina and Gloria got on when she first started dating Bradley. However, following their rows, Bradley is said to have sided with his mother, with whom he is incredibly close.
The source added to The Sun newspaper: "Bradley's mum and Irina were quite close at the start of last year but the more time they spent together the more they realised that they didn't get on.
"That caused friction between Bradley and Irina as he is very close to his mum and the fact that Irina and her didn't get on put pressure on their relationship.
"Irina is a very strong, beautiful Russian woman who knows what she wants, and perhaps Bradley's mum saw that as something she didn't want for her son."
The publication also alleged that Irina has already moved on from the relationship, and is said to have been growing closer to male model Stephen James, who she has starred with in numerous campaigns.