Unfortunately, I am feeling the same as you think. They are not a couple anymore, they even don't have an open relationship. They are two individuals living together and fucking time to time. That's it. I stop reading the stories anymore. I just treat this game like all the others right now. A good looking sexy woman fucks lots of men.
And you are so right. The emotional bond is (should be) the key here. All men are (should be) like toys for a couple. It is (should be) like using a vibrator while you are looking into your partner's eyes. And sharing/swinging/cuckolding is not suitable for weed emotional bounded couples. I am writing this so confidently because my last long relationship was sharing/swinging relationship and we never looked the others as potential partners. They were our friends, lovers, toys. But most of the time if it is possible we were holding hands while were with others.
I lost my hope for this game. I hope it will turn to the original idea as adventures of a couple but I think it is nearly impossible right now after the last update where Anne started to fall in love with the other men.
Sad...
Still, it is just a game and Ann is a sexy character... Rather than reading the script, I am creating my version of stories in my head