She was hired to appear in the US star’s movies The 40-Year-Old Virgin in 2005 and Knocked Up in 2007.
It was in between making these films that Stormy claims she had a sexual encounter with the then tycoon before he became US President.
Comedian and director Seth, 37, who co-wrote the movie Superbad, told The Graham Norton Show last night: “Back then she told us she had slept with Donald Trump but hearing that a porn star had slept with him wasn’t interesting at all and we weren’t shocked because it was expected information.
“Years later it became very relevant information and I wondered if I should say something.”
Stormy, 40, alleges she was paid £100,000 and signed a non-disclosure agreement to stop her discussing it.
She later claimed the agreement was invalid as Mr Trump had not personally signed it.