Another intriguing implication of the difference between circumcised and intact males is the question of self-cuckoldry. Put another way, is it possible (short of artificial insemination) for a women to become pregnant by a man she never had sex with? We think the answer is “yes.”
To pump out the last guys load.
There's speculation that's exactly the reason the under head of the penis is shaped that way.
I read a post some time ago that squirrels have a bone in the penis shaped as a scoop exactly for this reason.
Googling "squirrel penis" but closing the shades first.
Quite a number of mammals have penis bones. Humans are actually the weird ones for not having one.
And still we call it a boner, double weird lol
I see you've also read
Semen Displacement as a Sperm Competition Strategy in Humans
Highlight of the summary:
It's the journey, not the destination, dammit
Yeah! Journey before destination!
This is my favorite one.
That's exactly why cats' penis have some hooks on it so it's stuck in there until everything is out !
Wikipedia NSFW