The former Pussycat Dolls star has met the pop heartthrob on a few occasions but she is always lost for words when he says hello.
Ashley was left similarly speechless when she bumped into 'The Other Woman' star Leslie Mann at a gym in Los Angeles.
She said: ''I've met Justin Timberlake a few times but I still don't know how to speak to him. Also, I saw Leslie Mann the other day - she's an amazing actress. She was at spin class in LA and I just shut down.''
Ashley, 33, would love to follow in the actress' footsteps one day and take a break from her music career to star in her a romantic comedy movie.
When asked about her plans for the future, Ashley said: ''To do a rom-com, have a house by the water and to go back to certain place in the South of France with a loved one where I once saw a couple laying on the beach - they looked so in love and the water was crashing about them. It was like a movie!''