United Kingdom, March 28 -- Some workers on The Comeback were left confused when Lisa Kudrow hugged Julian Murray Stern on set - unaware he was her son.

The 62-year-old actress believes the affectionate greeting may have made a few people think it was an inappropriate moment.

Lisa recalled to People: "I was kind of tired, and my brain was just a little fuzzy, and I've been looking at lines.

"I walked in, and I saw Julian sitting on the couch with some other people, like, 'Oh,' and just walked over and climbed onto the couch right next to him and cuddled in.

"And everyone just went ... And he went, 'Hi, Mom,' and everyone was looking. It was maybe inappropriate just like to climb on him. I think some people didn't know he was my son. S...