The MC is the guy that Anne truly wants to be her husband. At the start of the game they have some sexual issues, that are maybe beginning to cast some doubts about them staying together. As the Adventurous Couple, these issues can be eventually overcome, but only if they learn to be honest with each other and share everything
There are a few things you swept under the rug, i'll elaborate.
A an adventurous couple, there are a lot of issues regarding their sex life being bland that they could overcome. The downside to where we currently are in the game is it's not an adventurous couple, it's Anne spreads her legs for whoever while Tony bangs his work collegues and Nicole, sometimes they chat about it.
That's the problem some people have with the game, it's lost the feeling of them being a couple.
When they have the heart to heart about honesty and 2 minutes later she's being finger banged and swallowing the cum of an old guy by the pool it kinda takes away from the moment.
The other glaring issue is Anne didn't have much of an issue with their sex life, it mainly came from him. So she's gone from doting wife that only had eyes for her man to wanting to fuck anything with a cock and a pulse. She's not fussy, young, old, any race, any size.
I don't believe that Anne loves Ryan more than the MC at all. In the throes of passion you can sometimes say or feel all kinds of stuff, that don't mean anything when it's all over. On the point of orgasm, I've told various people that I love them, only to wonder why I said such a thing later. What matters is how you feel when your emotions are no longer a slave to the intense feelings that you experience during sex.
If Anne really loved Ryan more than the MC, she would have dumped him by now, and moved in with Ryan. But she doesn't, because it's actually the other way round. The MC offers her the kind of stability that Ryan is incapable of. He's kind, thoughtful and willing to do anything to satisfy his wife. And you've got to ask would Ryan accept the new lifestyle, that both Anne and the MC are now enjoying so much? Ryan has already stated that he couldn't handle it. So why would Anne choose someone who would try to stop her from having the fun she now loves, over someone who actively encouraged it?
And Anne might love Martin's cock, but he's a serial womaniser, who never spends more than a few nights in one place, and he's only really devoted to one thing, his business. Martin is not a good prospect as a husband. Him and Anne would never be able to settle down, in the way that Anne and the MC have. Anne may view Martin as a terrific lover, but that's as far as it goes.
There is a scene where Anne flat out admits she has feelings for Ryan and is willing to cheat on her husband with both him and Martin.
When you confront Anne for cheating with Ryan if you choose to do so she doesn't tell Tony she loves him more and wants their relationship to work, she gaslights him and turns the argument back around on him guilting her way out of it.
She is willing, on many occasions, to cheat on her husband.
The whole thing with Martin is a fucking joke in itself. He's done this before.
Now When Anne admits what is going on Tony does absolutely nothing. You get no choices to tell her to leave or walk out, nothing. The only reason they didn't split is plot armour.
First she admits to cheating on her husband with his own father, sees it hurts him and the next day she's still doing it.
She may not be willing to leave Tony but it's painfully obvious she has feelings for both Ryan and Martin and would be with either of them within seconds of her marriage falling apart.
That right there is the biggest downside to this game.
Anne can basically do what she wants with no consequences. She can cheat, she can fuck around and she can do so because nothing can go wrong for her.