come on to （对异性）献殷勤

I met a guy at a party and he came on to me real hard.

我在聚会上遇见一个小伙子，他对我大献殷勤。

You are coming on to me. I have to tell you. You got no chance.

你对我献殷勤啊。不过我必须告诉你，你没机会。