Before he was twenty, George Seton married Isabel, daughter and heiress of Sir William Hamilton of Sanquhar, at the time one of the Senators of the College of Justice and Captain of Edinburgh Castle. 

She brought him the Manor of Sorn and other lands in Kyle, which lands were later confirmed on their youngest son Sir William Seton of Kylesmuir, Knight, who was named after his maternal grandfather, and who was himself Chamberlain to the Hamilton Earl of Arran, his uncle. 

A number of gold medals were struck to commemorate this union, on account, especially, of the bride’s relationship to the Earl of Arran, Regent of Scotland and Duke of Chatellerault in France.  The medal above is now very rare, and is described by Francisque Michel in his Civilization in Scotland.

Sir William Hamilton of Sanquhar, Isabel's father (Lord Treasurer to James V), and George Seton, 6th Lord Seton, invited his Majesty to Sorn Castle, in Ayrshire, to be present at the marriage of his daughter to the future 7th Lord Seton. 

On the eve of the appointed day the king set out on the journey; “but he had to traverse a long and dreadry tract of moor, moss, and miry clay, where there was neither road nor bridge; and when about half-way from Glasgow, he rode his horse into a quagmire, and was with difficulty extricated from his perilous seat on the saddle. 

Far from a house, exposed to the bleak wind of a cold day, and environed on all sides by a cheerless moor, he was compelled to take a cold refreshment in no better position than by the side of a very prosaic well; and he at length declared, with more pettishness than wit, that ‘if he were to play a trick on the devil, he would send him to a bridal at Sorn in the middle of winter.’ 

The well at which he sat and swore is still there and is called the King’s Well; and the quagmire in which his horse floundered is ironically called the King’s Stable, from His Majesty's note that his horse was now truly stabled there.