New Scientist did research and concluded that putting bread and cake in the fridge actually makes them go stale faster. So take it out and tell your flatmate you're trying to help him/her out.
My dad does this and he insists it keeps it fresh despite me telling him the science of why it does the opposite. So I just leave the bread out and love seeing him get annoyed, he blames me for leaving it out, I blame him for putting it in the fridge. It’s a never ending cycle