That was really interesting to read. I totally empathize with you about moving slow. I agree with SNeacail that perhaps they should be the ones to find an alternate occasion for the time being. If it would help you adjust. Gosh, they really just need to build houses for poly people with a metamour chamber. With an option for sound proof walls.
My SO keeps suggesting to me that I find other men to be sexually active with as he and I have a lot of limits in place from his wife but I keep trying to explain to him that I can't just meet some guy and go for it. There's a whole process that needs to happen first and I can't force it. I'm glad I'm not the only one that moves like a snail.
I hope that you guys can find a good resolution so that you can all feel good about the relationship.