My mil has been over every single day for a week+

My husband keeps on inviting her over, she’s been over every single day for the past week. I told him it was too much, I enjoy my alone time and get overwhelmed with having guests over all the time and that once a week was enough, and guess who just showed up again today? My mil. What am I supposed to do? I already told my husband it was too much. I don’t want to be the bad guy. 😫