My girlfriend slept all day. I really want to tease her that she is a lazy pig. What should I say?

Little lazy boy sounds much better than little lazy pig. After all, pig is not a particularly good word, and if your girlfriend is a little fat.

So let's talk about lazy boy.

You can tease her and say, little slacker, have you just woken up? I want to talk to you, but I don't want to disturb you when I know you are sleeping.