Hi Lostsoul. I hope I can be of some help.

Don't worry...I don't think anyone is going to beat you up. I am going to address the affair aspect of it, but you won't be judged here.

Speaking specifically to the scat fetish without any other factors considered, I'd tell you that if you're not into it, you simply are not into it. Don't, regardless of what it is, let yourself be talked into doing something you aren't comfortable with. If you don't want to do it, don't do it. Simple as that. If it's significant enough for him that it signals overall incompatibility, I'd say you two are simply incompatible.

That aside, I do think that in the long term, it's more beneficial to you to address your marital status before doing anything else. Part of me fears that due to the stress of your husband's abrupt emotional end to the marriage in his announcement, you're, possibly, more attracted to this guy than you would be otherwise, and are possibly overlooking flaws or downplaying them in order to keep him. You've already noted in no uncertain terms your disgust for the fetish, yet you did mention you considered it. That's my signal there.

Outside of that, it's ultimately for the best for both you and your husband to either end things amicably or to try to work things out. Right now, your current situation isn't, in the long run, going to help either one of you. Additionally, the scat guy (sorry...don't know how else to address him) needs to do the same with his gf. Things like this, in my experience, tend to hit a breaking point, and hurt a lot of people. Don't get me wrong...not at all judging you, as I appreciate what a horrific shock your husband's admission must be to you, and I can't say with certainty how I would handle it if I were in your shoes. I just think it's best to work on you before you work on these other things, including either relationship.

Hugs, and I hope things work out for the best,
Harley