My friend made a cake for me, and put jam and whipped cream inside instead of the usual icing. I'm storing it in a sealed plastic container in the fridge, but how long will it last before the cream starts getting a bit dodgy? It was made friday evening, but it's a big cake and I can only manage a couple of slices a day and my weird family don't like cake so I still have half left! I don't want to give myself food poisoning!