chat someone up
phrasal verb with chat verb [ I ] uk/tʃæt/ us/tʃæt/ -tt-
UK informal
B2 与…搭讪;与…调情
to talk to someone in a way that shows that you are sexually attracted to them
He spent all evening chatting her up and buying her drinks. 他一晚上都在跟她调情，给她买酒。