Weston's past is troubled: his wife died in childbirth, and he lost his child as well, according to Daily Express - Showbiz. He had multiple restraining orders taken out against him for domestic violence, and previously worked in cryptocurrency before joining Gilead. Agnes' stepmother Paula disclosed that Weston remained eager to pursue Agnes, and hinted at his sinister plans in a one-to-one chat.
According to Daily Express - Showbiz, Paula described that Commander Weston likes a challenge and still wants Agnes, comparing breaking her spirit to breaking a horse. It is heavily implied that Weston still wants to marry Agnes because he plans on violently disciplining her into submission. Whether Weston will harm Agnes if they marry remains unknown, as does why Paula is willing to marry her off to a known abuser.
I only hope I can measure up to your expectations of a wife. Especially given you've been married before.
My wife died in childbirth. It was the worst day of my life, the day I lost my child.
It seems Commander Weston likes a challenge. He still wants you. Men like that enjoy a stubborn spirit. It's no fun breaking in a horse that's docile.