Cameron Diaz has reportedly been getting close to Lady Gaga's boyfriend.
Blonde beauty Cameron is currently filming new romantic comedy 'The Other Woman' with Taylor Kinney - the 'Edge of Glory' singer's partner of two years - and the pair are said to have bonded both on and off screen, resulting in a "stressful time" for the singer.
A source told The Sun newspaper: "This isn't going down well. Cameron and Taylor have clicked on set and are getting on really well. They've been hanging out and the news has reached Gaga's camp.
"It's been a stressful time for Gaga with this on her plate as she's recovering from hip surgery."
Cameron, 40, has reportedly been spending lots of time with the 31-year-old hunk, including trips to cafes and restaurants during breaks in filming - and Taylor is said to have introduced the 'Bad Teacher' actress to his family.
The source added: "Taylor has the perfect excuse for going for days out with Cameron as they're workmates, but they're not just being close at work.
"Cameron and Taylor have been seen in cafes and went out for dinner. They were joined at the hip at a drinks party for [co-star] Kate Upton's birthday.
"Cameron also met Taylor's family as his brothers Adam and Trent have visited the set."
'Bad Romance' singer Gaga - who is recovering from hip surgery after a labral tear forced her to cancel dates of her Born This Way Ball tour earlier this year - may be at further unease as pictures surfaced of the film stars sharing a steamy kiss in character for the film last week.
'The Other Woman', which also stars comedic actress Leslie Mann and 'Game of Thrones' hunk Nikolaj Coster-Waldau, is about a woman who learns her boyfriend is a married man and hatches a revenge plot with his wife.