Large girl having two husbands? (6)
I believe the answer is:
bigamy
'having two husbands?' is the definition.
(I've seen this before)
'large girl' is the wordplay.
'large' becomes 'big' (synonyms).
'girl' becomes 'amy'.
'big'+'amy'='BIGAMY'
(Other definitions for bigamy that I've seen before include "Having more than one spouse, illegally" , "Instance of having two spouses" , "overmatiness" , "having two husbands?" , "Crime of marrying when already legally wed" .)