Cats strange behaviour?

3 nights ago my 4 year old cat who is a huge baby n very smart(no accidents ever) decided to do a poo on the kitchen surface!! the next 2 nights hes peed on the stainless steel hob grrrr this is driving me crazy n i have no idea why he doing it, he has a litter tray which he always uses when indoor, the tray is clean, the litter was a day old with no poo's in it, we havnt recently changed brand of cat litter so im really confused, he normally good as gold, and is also neutered