Ty - who plays young Aegon II Targaryen in House of the Dragon - was adopted by David the same year the BAFTA host married Ty's mother Georgia.
Actor David Tennant will host BAFTA's latest Film Awards for the second year in a row later this weekend.
David is best known for his role on the revived Doctor Who, with him having played the Tenth Doctor on the BBC show.
His other projects include a podcast, David Tennant Does A Podcast With…, which is set to return for a new series this year.
Their family now also includes David and Georgia's five children, like Ty Tennant, 22.
