Angelina I agree with the first part, but I don't know if I share the conclusions. it would then mean more restrictions for both sides than now, but maybe it's a good way
Well, Christine does not tolerate her mother to "sleep around". So the "no sex but masturbation is allowed" policy is what reflects Christine's values. And that means those values should apply to her, rather than Christine just projecting those values onto her mother.
I know that would result in both being more restricted, but it is better to live acording to your own values - even if that is not always convenient or comfortable - rather than just projecting those onto other people.