Beth sy’n digwydd pan fydd Mab Cyntaf America yn syrthio mewn cariad â ‘Thywysog Cymru’? Mae Alex Claremont-Diaz yn olygus, yn garismatig a’n athrylith – aur pur marchnata i’r Tŷ Gwyn ers i’w fam ddod yn Arlywydd yr Unol Daleithiau am y tro cyntaf. Dim ond un broblem: pan fydd y tabloidau yn cael gafael ar lun yn ymwneud ag anghydfod rhwng Alex a’r Tywysog Henry, mae’r cysylltiadau rhwng yr UD a Phrydain yn cymryd tro er gwaeth.

Mae penaethiaid teulu a gwladwriaeth yn dyfeisio cynllun: cynnal cadoediad. Ond mae’r cyfeillgarwch ffug yn tyfu’n ddyfnach, a’n fwy peryglus, nag y gallai Alex neu Henry fod wedi’i ddychmygu.

What happens when America’s First Son falls in love with the Prince of Wales? Alex Claremont-Diaz is handsome, charismatic, a genius – pure millennial-marketing gold for the White House ever since his mother first became President of the United States. There’s only one problem. When the tabloids get hold of a photo involving an altercation between Alex and Prince Henry, U.S./British relations take a turn for the worse.

Heads of family and state devise a plan for damage control: stage a truce. But what begins as a fake, Instagrammable friendship grows deeper, and more dangerous, than either Alex or Henry could have imagined. Soon they are hurtling into a secret romance that could derail the presidential campaign and upend two nations.