Sometime Lover

I am not a piece in a chess game that you get to play every time you are in the mood. 

My love is not a pawn you can cash in when it is convenient for you. 

You don't get to need me and then desert me when you don't anymore. 

What are you doing this for? 

I don't deserve only a part of your heart when I've given you all of mine. 

I don't know why I expected any different, you do this every time.
'Sometime Lovers' always do.....