bags...

bags on (something)

slang The right to possess or take something, or the rights to have first choice of something; dibs on (something). "Bags" are usually claimed verbally. Primarily heard in UK. I call bags on the front seat! Hey, I had bags on being first in line!
See also: bag, on
Farlex Dictionary of Idioms.

bags (I)...

(British English) (American English ˈdibs on...) (informal) used especially by children for claiming the right to have or do something before anyone else: Bags I sit in the front seat!
Farlex Partner Idioms Dictionary
See also:
  • (first) dibs (on something)
  • a fast talker
  • (you) wanna make something of it?
  • all for the best
  • (do) (you) want to make something of it?
  • a/the feel of (something)
  • (I) wouldn't (do something) if I were you
  • a walking
  • a walking (something)
  • a straw will show which way the wind blows