If the account in Revelation and what Jesus said to his apostles about the 144,000 and Great Crowd are blended together you get a better picture.
1. Jesus returns to earth after the great tribulation.
2. New Jerusalem comes down from heaven. Sits on a lofty mountain top.
3. Jesus is King and temporarily sits on God's throne here on earth. Jesus is Eternal Father(new Adam), Mighty God. He will take on physical form but he will be able to phase in and out just like after his resurrection.
4. A special group of people work with Jesus around the temple to be counselors and advisors to the nations. This is the 144,000, but the number is not literal because it's too conveniently rounded. It's just a symbolic big number that is associated with the original Israel arrangement. This group will most likely not have married, just like Jesus.
5. After a long period of time Jesus puts everything back together here on earth. Jesus then gives the throne back to his Father. The throne seat will probably be empty when that happens. That's the way God wanted it in the first place. People will know who really sits in that chair but he doesn't have to.