Popular and married, yet sadly broker (12)
I believe the answer is:
intermediary
'broker' is the definition.
(thesaurus)
'popular and married yet sadly' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'and' means one lot of letters go next to another.
'sadly' is an anagram indicator.
'married'+'yet'='marriedyet'
'marriedyet' is an anagram of 'termediary'.
'in'+'termediary'='INTERMEDIARY'
(Other definitions for intermediary that I've seen before include "Go-between" , "Negotiator" , "Agent" .)