> In a letter to his brother Leopold, Grand Duke of Tuscany, Joseph II described them as "a couple of complete blunderers."[50] He disclosed to Leopold that the inexperienced—then still only 22-year-old—Louis XVI had confided in him the course of action he had been undertaking in their marital bed; saying Louis XVI "introduces the member," but then "stays there without moving for about two minutes," withdraws without having completed the act and "bids goodnight."
https://en.wikipedia.org/wiki/Marie_Antoinette#Motherhood,_c...