try on with
try it on with (one)
To attempt to have sex with one. Primarily heard in UK. My boyfriend got drunk and tried it on with one of my friends, so I broke up with him right then and there. I heard she tried it on with one of the groomsmen during the reception.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
try something on with someone
to get someone's opinion about an idea or plan. Let me try this idea on with you. She tried the new idea on with the boss, but the response was not good.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.