So, these four guys had, for years, taken a weeklong backpacking trip every year. This year, Fred had some bad news for his buddies: "My wife says 20 years of these trips is long enough, and that if I waste another week of vacation on one this year, we're finished. So, I guess I won't be going."
The other three were disappointed, to say the least, but went on the trip without Fred. When they arrived at the trailhead, there was Fred, pack on his back and poles in his hand!
"What happened? How come you're here?" they asked.
"Well," said Fred, "my wife was reading Fifty Shades of Gray. One night, she pulled me into the bedroom and pointed to some ropes and handcuffs on the bed. She told me to tie her to the bed, so I did. The she told me to do whatever I wanted."
"And here I am!"