Angelina Jolie's adopted son Maddox shocked crew members at a recent photo shoot in California - by calling Brad Pitt "Daddy".
Jolie and Pitt have repeatedly denied reports they are a couple, since Pitt and Aniston ended their five-year marriage in January.
But photographs of the couple travelling around Africa and Europe with Maddox have fuelled rumours they are secretly dating.
Pitt has always wanted to become a father, and has had such a powerful effect on Jolie's three-year-old, he now regards him as his dad, reports British newspaper The Sun.
A shocked witness says: "Maddox shouted, 'Where's my daddy? I can't see my daddy?'
"Crew members were truly taken aback that he was referring to Brad as 'Daddy'."