That first one, the all black one, just screams drake to me. The size, the thick legs, the large face mask. The other one, I'm not 100%. More pictures would definitely help. It's much easier to sex muscovies if you have a bunch to compare to each other The size is usually the giveaway.
Thank you so much!!! She/he (the black one) is the more aggressive one and has tried to take a bite out of us so it's not a surprise that you think she/he is a male. The other one is not aggressive but is about the same size and has about the same facial markings. The person who came over( I'm going to stop using the word duck expert) said that they were over fed but we don't feed them a ton so if thats true maybe thats the reason why they are so big.