Angelina Jolie and Brad Pitt pose at the AFI Awards 2014 honoring excellence in film and television in Beverly Hills, California, Jan. 9, 2015. REUTERS/KEVORK DJANSEZIAN

Brad Pitt was caught kissing his co-star Lizzy Caplan amid growing rumors that he and his wife Angelina Jolie are headed for a divorce, Radar Online reported late Sunday. Photos of Pitt sharing a passionate kiss with Lizzy Caplan while shooting for a film in London were posted by Radar Online.

According to several reports, Jolie and Pitt have been going through severe marriage troubles over the last few months. Some speculate that the growing tensions between the two have caused Jolie serious health issues, bringing her weight down to 79 pounds. On Friday, Daily Mail reported that Pitt was seen filming emotional scenes with Caplan on the sets of his upcoming World War II drama "Allied."

Pitt has been surrounded by several cheating rumors since reports surfaced that he and his wife were living separate lives. Most recently, Star magazine reported that the actor was getting cozy with his co-star Marion Cotillard. The report also stated that Pitt and Cotillard have “affectionate nicknames” for each other and “secret in-jokes that no one else gets.”

Several reports have claimed that Jolie was paranoid over Pitt's flirting, and this was tearing their marriage apart. However, Radar Online reported, citing a source, that the main problem between Jolie and Pitt was over marriage responsibilities.

"They're at war over who's looking after the kids since that agreement got blown out the window with her desire to turn her directing career into a success after several failures," the source reportedly said, adding that Pitt's return to the shooting increased the fights as "all of this is not sitting well with his wife."

Meanwhile, the National Enquirer earlier reported that Pitt was "at the end of his rope" over his wife's reluctance to address her health issue.

"Brad has done everything to get Angie to focus on her health and well-being," another source told National Enquirer. "He's watched in despair as Angie sometimes goes all day without eating a solid meal and watched as well as she's sometimes slept in to the late afternoon because she doesn't have the energy to get out of bed."