Don still sleeping around (3,2)
I believe the answer is:
put on
'don' is the definition.
(I know that don can be written as put on)
'still sleeping around' is the wordplay.
'still sleeping' becomes 'not up' (not up out of bed).
'around' says the letters should be written in reverse.
'notup' back-to-front is 'PUT-ON'.
(Other definitions for put on that I've seen before include "Assume < present" , "in an unnatural way" , "Donned" , "Don clothes or stage play" , "Increase as with weight" .)