From GRRM's (not a) blog:
He's a father, he's a son. He's been a bishop, a cardinal, a prior, a friar, a vicar, a knight, a lord, a mayor, a director. There's one born every minute, but by any other name he'd smell as sweet.
I see the long delay between visits from Froggy the Gremlin hasn't dulled your skill at deciphering clues any.
Yes, it's the fine British character actor Roger Ashton-Griffiths, who has been cast in the role of Mace Tyrell, son to the Queen of Thorns, and father of Loras and Margaery.