The perk Nuki Nuts dosn't work

[Rybny]

The balls, according to the perk should expand and yet nothing happens.
The version is 0.2.3

 

[Upcast Drake]

They expand if you haven't cum in a while. They grow to 4x the size if you are at maximum ball-fullness, which by default would take 2 days if your balls are totally empty. The character in the save you posted has a base ball size of 11.75, but they are at maximum ball-fullness, giving them a ball size of 47. The appearance screen describes them as apple-sized when empty and watermelon-sized when full.