Oh, good gravy. If it’s important to your hosts, go to the designated area to nurse your baby. Or politely decline the invitation, but keep your nutcase gripes to yourself.
My sister tried this at our engagement party years ago. We took her to a bedroom at the back of the house for privacy. She could not(or refused)to understand why.
It was not her first child... I guess we needed to accommodate her in the middle of the living room.