You don't have to keep tellnig him no. I'd tell him no one last time and that would be it. I'm a sahm and I love it. But...if someone didn't want to do it, it could be hell. It will end up negatively affecting the entire family if you don't want to be at home and you are. Tell him that, and ask him if that's what he would rather.
Yes I am a nanny but I don't consider it basically a SAHM. I have to get up at a certain time every day, just like any other job. I have things I need to get done during the day, just like any other job. I get a paycheck, just like any other job.
I like it because I can do this and not have to worry about daycare. My kid comes with me.
Aren't you a nanny? That's just like a SAHM just with other peoples kids and you get paid! Do what makes you happy, being a SAHM isn't for everyone.