It's my fault husband has left rings (4)
I believe the answer is:
oops
'it's my fault' is the definition.
'husband has left rings' is the wordplay.
I cannot quite understand how this works, but
'rings' could be 'oo' (two O's - O resembles a ring) and 'oo' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for oops that I've seen before include "I'm sorry" , "Exclamation on making obvious mistake" , "Something's been spilt!" , "I've slipped" , "Clumsy me!" .)