in the Christmas special she's pregnant, and they have a kid, and then right after the baby is born (like, going from the hospital to Downton to summon the rest of the family) he dies in a car crash
I can't decide if it's better or worse than "Matthew's dead ex tells Mary and Matthew to hook up via an Ouija board" which is how the S2 Christmas special ended lol
but at least his penis did its duty
that's the other wtf thing I remember