While in town supporting fiancee Angelina Jolie, who was in London co-hosting the Global Summit to End Sexual Violence In Conflict, Pitt "bumped into” Holmes in the middle of the lobby of the Hilton London Syon Park hotel, the source tells Us.
For five minutes, the 50-year-old and the 35-year-old (who was in London shooting new flick Woman in Gold) talked about everything from show business to their kids. The onlooker tells Us Holmes praised Jolie's humanitarian work, while Pitt asked Tom Cruise's ex-wife if daughter Suri, 8, was "off having fun.” (Pitt and Jolie's daughters Shiloh, 8, and Zahara, 9, are close in age to Suri.)
"They seemed really happy to talk and were both giggling," the source tells Us.
For more details on Pitt and Holmes' run-in, watch this week's Hot Stuff video, as explained by Us Weekly Entertainment Director Ian Drew and special guest Marissa Hermer from Bravo's latest reality show Ladies of London.
Also in the roundup: Courteney Cox celebrates her 50th birthday and much more!