My drakes can be real pains but they haven't carried it to this extreme about not letting one of the girls eat, but since I have 43 in my flock not all ducks I have many feeders and water buckets out. might make a difference, have you tried putting out more than one feeder and bucket for water...
Might work since when your with them he doesn't chase the girls, I noticed your one has angel wing but I still think you'd be able to see the drake feather since it's down at tip of tail lower back. Ming is just at the age where hormones are rampant, keep letting them have time together in the...
Even ducks will act out the mating ritual so it may not be a male, the drake feather at base of tail should be curled upward if drake. anytime new ducks are added it's best to introduce slowly put Ming in a separate part of your pen and coop with temp fencing so he can't get to your 2 ducks...