A VERY oily pimple inside the penis canal and sometimes the greese can leak out of the penis at random times. This may accur in some women if they leave a tampon in their vagina for more than 48 hours at a time.
If a man has a Greese Cake, it will block his urine canal and he cannot have sex. If sperm is cought in path this way, the man's penis may reject the passage used and will come out the nipples instead.
My doctor told me the only way to pop my greese cake is to jam a needle or something small like a paperclip inside and try to pop it.