I also had such a problem with my kids and when I stopped to force them they joined me. And my advice is not to say anything, they will come with initiative, I think that we need a guide to help us to speak with them. However, what yoga mats do you use? I found on the Internet
top 10 best yoga mats and I was surprised of how different mats can be. I didn't pay attention to the mat before, I was just buying the cheapest one, but now I have 7 different yoga mats (bought them for my children and their friends because they also join me). I am waiting for your reply.