"I've never had to pretend to be having sex with somebody. I'm like the queen of the foreplay dissolve"

Julia Roberts is referring to her acting profession and the roles she has taken on. She is suggesting that she has never ever had to act out a scene where she is pretending to make love with somebody. Instead, she has actually been able to take on functions that concentrate on the build up to the sexual act, or the "foreplay". She is proud of her ability to depict these scenes in a credible and realistic method, and she is jokingly referring to herself as the "queen of the foreplay liquify". This quote is a testimony to her skill as a starlet and her ability to bring a scene to life without having to resort to explicit sexual content.