Because if you added one more it'd be two farty.
Clickbait. Edit: Added a space which triggered someone.
Calc you later!
Mashed potatoes...
One's a tragic Mick...
Human Beans.
How you bean doing.
Just two. It only requires that either the people are very small or the light bulb is very large.
The supreme commander didn't have the balls required.
If there were one more it would be two-farty!
Because if there were one more, it'd be two forty. (Too farty) This works much better when spoken out loud. The joke how Irish people pronounce "forty."