"When I told my daughter that I was shooting the scene that day she spluttered... I took it to be jealousy. But I did feel quite bad for Liam. He's a sweet guy but I couldn't stop giggling," said the 40-year-old actress.
In the upcoming film, set in the 1950s, Hemsworth, 25, plays Winslet's love interest, and the pair get steamy in several scenes.
The Oscar-winning actress said her daughter has a crush on Hemsworth.