Mom keeps asking about divorce

My mom and most of my family wants to know why me and my husband are getting divorced especially when we have 5 kids and I honestly don't want to get into it. He didn't cheat. Long story short, my husband is gay. I'm not going to talk on here about it. Please don't comment horrible things about my husband. I just want to have a decent co-parenting relationship and quite frankly don't believe it's my family's business. I would never out someone. I don't want to hurt him. Plus hurting him would be hurting my children. What do I say to my mom when she keeps asking because she won't stop asking. I know people will say she's my mom but this is something I'm keeping between me and my husband.