express to on

express (oneself) to (someone) on (someone or something)

To share one's thoughts on someone or something. Well, did you express yourself to David on that problem? He's not a mind-reader, you know. I never expressed myself to anyone on Laura—how did they know I have a crush on her?
See also: express, on

express (oneself) to someone on something

to say what one thinks about something. I will express myself to Karen on that matter at another time. She expressed herself on Karen to the entire group.
See also: express, on