let (one's) heart rule (one's) head

let (one's) heart rule (one's) head

To do something based on one's own personal desires rather than for pragmatic or practical reasons. I couldn't believe it when I heard he'd bought a sports car, but then he has always been one to let his heart rule his head. I think she knows that a relationship with him will eventually end in tears, but she's letting her heart rule her head.
See also: head, heart, let, rule
Farlex Dictionary of Idioms.

let your ˌheart rule your ˈhead

act according to what you feel rather than what you think is sensible: Don’t let your heart rule your head. I know you like him but are you sure you can really trust him?
See also: head, heart, let, rule
Farlex Partner Idioms Dictionary
See also:
  • at will
  • run (one's) own show
  • run one's own show
  • get past
  • get past (oneself)
  • get/have your way
  • get (one's) (own) way
  • get one's way
  • (one's) true colours
  • make to order