Pregnancy cake

When a man doesn't clean his ejaculatory residue off from his bellend for weeks/months/years, until the top of his penis resembles a frosted cake. (some might be inclined to add extra cake decorations to penis)

The man then proceeds to fuck his lover, thus giving her 'the pregnancy cake.'

"Frank, I can't lie to you, I saved up for months and gave your girlfriend my pregnancy cake...

I promise, I'll let you know if she tells me she's pregnant, sorry bud."