Any thoughts about Cuck-sitting?

I often think about how it would be for a cuckold to have a cuck-sitter, i.e. a minder who watches over him while his wife is with her lover.
Depending on the preferences of those involved, it could also go beyond supervision and the cuckold must be available to the cuck-sitter for other things.

I’m only a wannabe, but in my arousing imagination that would be my wife’s sister. She lives with her adult daughter and they would be a perfect team for this! The sister is more the very fast, busy type. She is a doer, spontaneous, demanding. Extremely quick decisions, not very willing to compromise. Her dominance is… well, let’s say she’s somewhat of a commander, but not as loud and serious. She acts a lot according to the principle “let’s go! Now don’t be like that and kindly do what I say, don’t argue pointlessly”.
Her husband probably couldn’t handle it for very long, which is why they broke up a long time ago.
The daughter is very different. She basically makes an extremely bored and somewhat exalted impression, often simply arrogant. Rolling eyes, probing questions about everything you say and do, purposeful ignoring. You always have the feeling with her (always!) that she is worlds smarter than you and you have to be glad that she even hangs with you. She has a very different dominance than her mother. Her principle is “You bore me, just do it, I know why and that must be enough for you”.
Despite their different personalities, the two women get along brilliantly.

Have you ever thought about something like this? What would be your favorite cuck sitter?