

It really depends, but ultimately a lot of social interactions can only happen between two people at once. Say you and your wife get into a fight. Instead of fighting it out & making up, she now has the option to stop fighting you and go hang out with your co-husband - and you aren’t invited. She also has the option to emotionally strong arm you to get her way by not only stonewalling you/withholding affection, but also by threatening to push you out of your marriage for another guy who literally lives with you both. Conversely, she does the same thing to the other guy.
Basically, now all those 2-person social interactions that happen in a marriage become much more complicated due to the presence of a 3rd person.
You’d need to have a lot of trust in your wife (and this other guy too) - she’d need to have a tremendous amount of emotional stability and be non-manipulative. She’d suddenly have a lot more power in the relationship in a very inequitable way.
My wife and I are very into monogamy. But she has a serious temper and can be very manipulative when she’s angry (she’s gotten better about this, but it’s a known issue). It’d be very easy for her to do something hurtful. I’m not talking about sex, just the emotional threat of turning to someone else for relief from me - and the implied threat of pushing me out.
It’s a pretty common occurrence for ADHD and Autistic folks. I’m a little bit autistic (Aspergers) and come from a family where literally everyone but me has ADHD, but I was always generally NT passing due to a lot of anxiety and really high levels of masking. I still am NT passing, but when I was informally diagnosed (by psychologists not psychiatrists) and agreed/identified with the label, I stopped masking as much. I don’t know how much other people noticed (they probably didn’t), but it was a big difference for me and allowed me to be more aware of the reasons behind some things that I feel and do - and to be able to forgive myself more for not being “normal”.
I don’t mask as much now, but I’m able to tell people things like “I’m sorry if what I said came off as me being angry or rude, I have a hard time monitoring the tone of my voice and I didn’t mean to come off that way”. So I have a better level of self-awareness and can still help other people understand my intentions & can communicate better without flat-out outing myself as autistic to other people.
Also though do please try to brush and floss regularly. Tooth pain/cavities/decay are no joke - you only get one set of those bad boys, gums don’t grow back, and you can’t really imagine how much it sucks to get nerve pain whenever you eat or drink things until it happens to you - then it’s too late. (No shame, only F E A R )