bacterial growth under an uncircumsised penis which isn't cleaned regularly, it looks like little pieces of cottage cheese under the foreskin, and it stinks.
a.k.a. smegma. forms under the foreskin of an uncircumcised penis when it has not been cleaned regularly. It is essentially dead/molting skin resulting from the foreskin keeping the glans penis moist.
I was going down on him and when I pulled back his foreskinthe head of his cock was caked with dick cheese