Reason baby Jesus felt husky at night … wet blanket? (3,2,3,6)
I believe the answer is:
dog in the manger
'wet blanket?' is the definition.
(thesaurus)
'reason baby jesus felt husky at night' is the wordplay.
I cannot quite see how this works, but
'at' could be 'in' (synonymous in some cases - eg at school, in school) and 'in' is located 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 dog in the manger that I've seen before include "One not letting others use what they themselves have no use for" , "One who won't let others enjoy what they have no use for" , "that could disrupt nativity play" , "possessive type?" , "party-pooper?" .)