It must have been a special birthday gift for Jeff this day as Luke allowed him to choose his own scene partner. After spending a lot of time in the gym it is obvious that he became enamored of Andrei Karenin's body and that influenced his choice this day. While Jeff has a great body and a super set of abs, it is true that not many other boys can compare with Andrei.
After watching the action of Andrei fucking Jeff I would say he made the perfect choice.