Normalcy and secure regularity mean the kids have to get used to you both being their parents even if you don't have a comfortable R between the two of you. It has little to do with either of your comfort, and all to do with your kids. You act civil and share that you are both there to support your kids.
That's co-parenting. That is the best for the kids. That is hard for the two of you. It won't be for that long. It is one evening, then a break. Won't it be even weirder that dad doesn't show up to be there for his kids to meet their teachers?
It really sounds like you might suggest some counseling on how to work together for the best for your kids during this difficult time. Not to work on your M, but how to have a good co-parenting relationship for them. You can always say, you don't feel like either of you (but certainly you - put it on yourself) knows enough about how to do best by the kids through all this, and you think you need some counseling to figure out what is best for them. Then suggest a family therapist who specializes in kids and adolescents. Our training paths combine marriage and family therapy, because you are always working with more than one person & managing the interpersonal dynamics is the focus. So, they will all be called Marriage and Family therapists/counselors. You emphasize the kids, and look for someone who really does focus on kids. If you can't find someone, look for someone who is just a regular therapist that specializes in kids. They may not have the particular training in negotiating the co-parenting R, but they will be able to help think through how to talk to and act that gives your kids the most of what they need right now.
Me: 50 W:43 S6, S3 M: 12 yrs. T: 17 M is bad & Not happy Bomb Mar '14 S 5 Feb '15 D Bomb 13 Apr '15 (but "no hurry") DB Coach May '15 Wants proceed on D Aug '15 Starting 1-on-1 negotiations Sept '15