oil and water mixing ?

i have a gilera runner 125 vx i have jus rebuilt the engine due to the oil being creamy so we have put all new gaskets on and rebuilt the bike then fired her back up and with new oil in within 5 mins it was all creamy again i no it is water gettin in the oil but from where now and its not jus seaping in it is dumping the water in there and there is no visible cracks