Wiktionary
cream up
vb. 1 (context transitive English) to cover with cream 2 (context intransitive English) to become creamy
Usage examples of "cream up".
My friend had already got a finger well greased with cold cream up Frank's fundament which the boy seemed to enjoy rather than not, as I might judge by the increasing activity of his little prick in my arse.
Gus got ice cream up the spoon handle, on his fingers, on his chin, on his T-shirt.