"Halloween Party" joke

A couple was invited to a masked Halloween Party. She got a terrible headache
and told her husband to go to the party alone. He, being a devoted husband,
protested, but she argued and said she was going to take some aspirin and go to
bed, and there was no need of his good time being spoiled by not going. So he
took his costume and away he went.
The wife, after sleeping soundly for one hour, awakened without pain, and as it
was still early, she decided to go to the party. In as much as her husband did
not know what her costume was, she thought she would have some fun by watching
her husband to see how he acted when she was not with him.
She joined the party and soon spotted her husband cavorting around on the dance
floor, dancing with every nice chick he could, and a little kiss here, a little
kiss there and sometimes a little bit more. His wife sidled up to him and being
a rather seductive woman herself, he left his partner high and dry and devoted
his time to the new stuff that had just arrived. She let him go as far as he
wished; naturally, since he was her husband.
Finally he whispered a little proposition in her ear and she agreed, so off they
went to one of the neighbouring rooms and did something which she would only
allow her husband to do. She was quite upset afterwards because her husband
could not know that she was his wife. She slipped away and went home and put the
costume away and got into bed, wondering what kind of explanation he would make
for his behaviour. She was sitting up reading when he came in and asked what
kind of a time he had.
He said, "Oh, you know I never have a good time when you are not there."
Then she asked, "Did you dance much?"
He replied, "I did not dance at all. When I got there I met Pete, Bill, John and
some other guys, so we went into the den and played poker all evening. But the
chap I lent my costume told me that he had a glorious evening."