Come and stay with me and do what you like! (2,2,5)
I believe the answer is:
be my guest
'come and' is the definition.
I can't tell whether this defines the answer.
'stay with me and do what you like' is the wordplay.
I cannot really understand how this works, but
'stay' could be 'be' (stay can mean to continue to be a certain way) and 'be' is located in the answer.
'you' could be 'u' (commonly used in online communication) and 'u' is located in the answer.
'like' could be 'y' (similar in meaning) and 'y' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for be my guest that I've seen before include "do stay with me" , "Please do!" , "Help yourself!" , "Do as you wish!" , "Go ahead" .)