<human>: Can you give me the gist of the text in a nutshell?

My [original post] didn't get a lot of attention, but I did get helpful advice (thanks!) and I have a new question, so here I am. I followed some of the advice I got, which was useful at the time, but I have an unfortunate update anyway. My SIL is back with her husband. 

After everything happened, my husband and I were relieved that we wouldn't have to spend any more time around her husband because he is bigoted, irresponsible, and very disrespectful/rude. We put up with him because we love SIL, but we were definitely relieved not to have him around. We gave her information and advice about how to proceed with the divorce stuff, helped around the house, and things were looking up. However, it appears she forgave him for the infidelity and they will be moving back in together. 

I still want to support my SIL, but honestly, I can't stand that man. I don't want to be around him, and I know that if we have to be around each other for family things I won't be civil, so we have kept away for now. I guess my question moving forward is, is it possible to be supportive for my SIL (in that she's still going through a tough time... plus I love her kid) without having to be around her shitty husband, or would that be in a way condoning a decision I'm 100% not a fan of? I know my own question doesn't make a lot of sense, I just want advice on how other people might approach the situation. 

Just a note for context: SIL is my husband's sister. Also, I did already recommend that she and he both get tested as well.
<bot>: SIL got back with her unfaithful husband. Any advice for how to still be supportive to her despite my loathing her husband (and the decision) would be appreciated.