i want to do a small gender reveal gathering with our family and a couple of friends. only thing is…

i want to do a small gender reveal gathering with our family and a couple of friends. only thing is hubby's mom and dad can not get along she finds a way to offend him and his wife. my step dad and dad only met once and had a fight. i think my step dad and dad will be civilized culturally (if my dad is sober)... my mom's house would be common ground but its nit in the best condition...i would love to fo it at my father in laws house...any advice ladies???