Actually, It's pretty in-character, considering how V always acts around Jasmine and other potential 'threats' like her and how desperate, for whatever reason, she is to convince the MC to propose to her, even after she got burned cuz of this type of thinking in at least a few past relationships.
The cuckquean path could very well be one big ass fan service to anyone interested in having the option for the MC to have sex with the many other girls without that many consequences, IF any at all, while still being on her path, especially since V thinks and most likely lies to herself she'll always be his number 1 or the queen in his harem of beautiful women. It doesn't make an ounce of sense for a supposed jealous and possessive woman like her to act like this, but porn 'logic' is again the answer to our questions.
Fictional bro there's on his way to become a modern-day version of an ancient king or a guy very very blessed with rizz, money and something else by momma nature to be able to get and keep all those women in his harem with the minimum amount of drama, so maybe the dick and the stability of a
somewhat secure relationship for once are the only reasons why V keeps holding on to this idea of what the MC supposedly is or can become as opposed to what he is in actuality.
Who knows ??
I for one definitely won't say no to a lil extra fun on the side, if this is what floats her boat.