Men's Nudism: Eroctopus Tentacles

A university research room. Hashiba, who works as an assistant for a professor known for being a little off, secretly has feelings for his boss.
Then one day, suddenly he and his privates are embraced by the professor.
"Ah! Not there!!"
In the blink of an eye his milk lands right on an octopus being experimented on...... .
......Then, the octopus starts acting weird!
"Wh......What the heck......is this...!!?...No! Oh no!"
What is the professor's objective as he observes hashiba's ecstasy!? Super thick tentacle.

from Renta!