:chuckle:
Nowhere do the scriptures say that David's throne is in heaven.
But they do say that the Lord Jesus is presently seated at the right hand of the Father....in the Father's throne.
David never had a throne in heaven!
David's throne has always been Jerusalem on this earth and ruling over the twelve tribes in the land promised to Abraham through Isaac and their descendants forever. Irrevocable!
2Sa 3:10  To translate the kingdom from the house of Saul, and to set up the throne of David over Israel and over Judah, from Dan even to Beersheba. 
1Ki 2:11  And the days that David reigned over Israel were forty years: seven years reigned he in Hebron, and thirty and three years reigned he in Jerusalem. 
1Ki 2:12  Then sat Solomon upon the throne of David his father; and his kingdom was established greatly.
1Ki 2:45  And king Solomon shall be blessed, and the throne of David shall be established before the LORD for ever. 
Psa 89:34  My covenant will I not break, nor alter the thing that is gone out of my lips. 
Psa 89:35  Once have I sworn by my holiness that I will not lie unto David. 
Psa 89:36  His seed shall endure for ever, and his throne as the sun before me. 
Isa 9:7  Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the LORD of hosts will perform this. 
Luk 1:32  He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: 
Luk 1:33  And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end.