tug at somebody's heartstrings
tear/tug/pull at/on (one's)/the heartstrings
To elicit strong feelings of sympathy or fondness. I don't know why, but that piece of music always tears at my heartstrings. That documentary really pulls on the heartstrings—you'll want to adopt all of those kids after watching it.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
tug at somebody’s ˈheartstringsmake somebody feel strong emotions of sadness and pity: Advertisers often use babies and children to tug at your heartstrings.
Farlex Partner Idioms Dictionary © Farlex 2017