In truth, acted deplorably — it means others shouldn't have to pay the price for you (5,5)
I believe the answer is:
dutch treat
'it means others shouldn't have to pay the price for you' is the definition.
(as in 'going Dutch' with a restaurant bill)
'in truth acted deplorably' is the wordplay.
'truth acted' can be anagrammed to 'DUTCH TREAT'.
Though, I am not clear how the anagram is indicated.
(Other definitions for dutch treat that I've seen before include "Outing with each paying their own bill" , "Shared expense" , "Occasion where everyone pays their share" , "delightful trip to tulip fields?" , "doing things individually?" .)