The joke is on who?

Matt tries telling Maddy the following joke the other day seeing if she could 'get' it.
Three women die and go to heaven. They are looking around and see ducks everywhere. Peter comes up to them and explains that they are not to step on a duck and if they do, there will be a punishment.
An hour goes by and the first lady accidently steps on a duck. Peter comes over and handcuffs her to a really ugly man. Six hours pass and the second lady accidently steps on a duck. Peter comes over and handcuffs an ugly man to her too. About a month passes and the third lady is doing a really good job of not stepping on the ducks but Peter approaches her and handcuffs this really handsome man to her. She turns to Peter and says, "but I haven't stepped on a duck!" Peter says, "I know, but he did!"
After Matt finishes the joke, Maddy says "I don't get it." Matt asks her what the punishment was for stepping on a duck. She replies, "being stuck with a man forever?"
I think she got it more than Matt wanted her to!