Upset, your party hosts stop talking (3,2)
I believe the answer is:
dry up
'stop talking' is the definition.
(dry up can mean to run out of things to say)
'upset your party hosts' is the wordplay.
'upset' says the letters should be written in reverse.
'your' becomes 'yr'.
'party' becomes 'dup' (Democratic Unionist Party).
'hosts' means one lot of letters goes inside another (inserted letters are welcomed or hosted).
'yr' back-to-front is 'ry'.
'ry' placed within 'dup' is 'DRY UP'.
(Other definitions for dry up that I've seen before include "Become parched or stop talking" , "Become waterless, or rude command to stop talking" , "Shrivel" , "Lose moisture? -shut your mouth!" , "Desiccate" .)