I don't think you're fat
A guy’s way of saying 'I don’t care if you’re a donut, I want to be your filling.'
'I don’t think you're fat, I think you're a donut I want to be the filling of.'
'I don’t think you're fat, I think you're a donut I’m going to eat.'
'I don’t think you're fat, I think you're the best donut I’ve ever seen.'