turn on the waterworks
US /tɜrn ɑn ðə ˈwɔtərˌwɜrks/
UK /tɜrn ɑn ðə ˈwɔtərˌwɜrks/

1.
开始哭泣, 掉眼泪
to start crying, especially in an exaggerated or insincere way to gain sympathy or attention
:
•
Every time she doesn't get her way, she turns on the waterworks.
每次她不如意,就开始哭泣。
•
He tried to turn on the waterworks to avoid getting a ticket, but the officer wasn't fooled.
他试图哭泣以避免罚单,但警官没有上当。