The second alleged victim, a parliamentary worker, was said to have been employed in her "dream job" when she found herself in Mr Elphicke's company sharing a bottle of champagne in April 2016, the court heard.
Ms Marshall said the witness described how Mr Elphicke allegedly assaulted her in Westminster.
The young woman said: "He fully came at me, pulled his body towards me.
"He had his face on (her) face. He had his mouth open, continually trying to kiss me. It was like a disgusting slobbery mess."
The prosecutor said the woman "clearly rejected" Mr Elphicke, told him he was married, and that there was a large age gap.
The prosecutor told the court the former MP allegedly "grabbed her hands and tried to kiss her again", adding that the alleged victim "knew she had to get out of there".
Mr Elphicke then allegedly behaved as if nothing had happened and went on to put his arms inside her coat.
Ms Marshall told jurors he said to the woman: "Oh I'm naughty sometimes aren't I? I can be so badly behaved but I can't help it."