make advances to (someone)
To approach someone in a flirtatious, amorous, or sexual manner; to try or begin to seduce someone. Terry was fired after he began making advances to his secretary. I really wish I could go out to a bar or a club without a half dozen men making advances to me.
make advances to someone
and make advances at someoneto flirt with someone; to begin to seduce someone. She began making advances to me, and I left the room. Mary made advances at every male she encountered.