"Up or Down?" joke

At the Senior Citizens' luncheon, an elderly gentleman and an elderly lady struck up
a conversation and discovered that they both loved to fish. Since both of them were
widowed they decided to go fishing together the next day.
The gentleman picked the lady up and they headed to the river to his fishing boat and
started out on their adventure. They were riding down the river when there was a
fork in the river and the gentleman asks the lady, "Do you want to go up or down?"
All of a sudden the lady stripped off her shirt and pants and made mad passionate
love to the man right in the boat. When finished the man couldn't believe what had
just happened, but he had just experienced the best sex that he'd had in years.
They fished for a while and then continued on down the river when soon they came
upon another fork in the river. He asked the lady, "Do you want to go up or down?"
There she went again, stripped off and made wild passionate love to him again.
This really impressed the old gentleman so he asked her to go fishing again the next
day. She said yes and so here they were the next day, riding in the boat when they
came upon the fork in the river and the gentleman asks, "Well, do you want to go up
or down?" The woman replied, "Down." A little puzzled, the gentleman drove the
boat down the river when he came upon another fork in the river and he asks the
lady, "Do you want to go up or down?" She replied, "Up." This really confused the
gentleman so he asks, "What's the deal? Every time yesterday that I asked you if you
wanted to go up or down you made mad passionate love to me. Now today, nothing."
She replied, "Well, yesterday I didn't have my hearing aid in and I thought you said
' fuck or drown'!"