Is OTHER wrong in the post ? POST : So this is a pretty simple one I suppose, petty as it is.

I come home and my housemate tells me I can have the rest of this pasta dish he's made. There's only a very small amount remaining; the size of the pan suggests to me that he's made a lot. I thank him and proceed to finish off most of it, but I still leave a bit.

Later on, he asks me to clean his pan because I had the last remaining morsel of food in it. I didn't know this was part of the deal, so I say no. 

If roles were reversed, I certainly wouldn't have held it to him to wash up my dish because he ate something like 5% of a meal I'd made. If it were me, I would have just let it go and washed my own dish, because I'd have made the food.

There's also a small bit of context I'd like to add for some perspective on this: I often find this housemate fairly untrustworthy. He steals others' food, constantly takes liberties and blags favours, and often it seems like he takes minor pride in being manipulative in small, petty ways. He has boasted about his food theft before, so for that reason I don't want to be nice to him. 

Is this a bias that is affecting my outlook on this particular situation, or is it really warranted that I should wash up a pan because he's given me some free food?