This is always the danger. And this game is a fine example.
Tony and Anne have been married for a while, the sex has become boring, Tony encourages Anne, Anne sleeps around, Anne enjoys sex again...
Now you can order what's the thing missing in Anne having sex and now enjoying it and say it's Tony so they are not suitable. You could argue no having sex with the same person just gets boring and it's the freshness of a new person.
I generally haven't been in these types of circles since my last partner died. I know couples who have made it work, I know couples who haven't generally if you set firm rules and stick to them you're fine...
The logical conclusion the paths to are I think as follows
The HotWife Path/Swingers path - this should end with both Tony and Anne still together embracing there sexuality, fantasies andbkinks
Anne Cheating Path - this will either end in divorce, or Anne leaving Tony for Martin, Drake Ryan etc etc it could have Tony being an ultimate cuck to bebfair
Both cheating path - should end in divorce regardless, the couple clearly aren't into each other
I know plenty of people who decided their partner was the reason they were not happy in a relationship.
I think some people just get into relationships without knowing who they are themselves, with high expectations etc.
There's been neighbours where I live running off with other neighbours, clearly just because someone showed them some attention etc.
As for the game, in my opinion, Anne just loves feeling special to someone she finds physically attractive.
She's kinda malleable when it's with other men. Extremely impulsive too, as we see whenever pushed.
Anne seemed to like being centre of attraction whenever groped in public.
I seriously feel she'd have eventually slept with other guys, even if Tony hadn't suggested it.
She loves feeling desired by other men, even emotionally connecting with a few of them.
She's not Tony's hotwife, she's a woman finally enjoying herself completely, while Tony watches.