It sounds like your husband got jealous of the attention you gave the other woman. He’s supposed to be the submissive, and you rule the roost, yet he got quite dominant in demanding you end it with the other sub.

The service sub sound like they are a house cleaner who doesn’t get paid? The way you describe how you help them to be better people sounds like you take on the role of strict parent/mentor.

My guess is your husband liked the dom/sub dynamic when it was just you two.