Weekly Riddle

This is a much harder riddle, and is all but impossible to figure out without help.

But, when you know the secret, you can make your own riddles like this!

 Many Legs

In comes two legs, carrying one leg, 

Sets down one leg on the three legs,

Out goes two legs, in comes four legs, 

Picks up one leg from the three legs, 

Out goes five legs, in comes two legs,

Looks at three legs without one leg,

Out storms two legs, in come seven legs,

Two legs throws the three legs at the four legs, 

Down goes one leg, into no leg.

What happened?

A woman comes into a kitchen, carrying a leg of mutton.

She puts it down onto a three legged  stool

woman leaves, and a dog (or cat)comes in.

Steals the leg (five legs = 4+1), and runs off. Meanwhile, the woman comes back,

sees the mutton is missing,

and storms off, and grabs the dog(seven legs=2+4+1)

and throws the stool at the naughty animal .

 The ruined mutton is thrown into the trash can.
Sorry for taking so long!
UPDATE: Thanks to Klenda For giving me this!