Shit you cant make up sis in law - mother in law edition

Military ball !!!........so my fiance has one coming up in may , my mom and dad are currently living in texas and my mom says " come for a whole weekend so we can buy your gown , theres a lady with such a beautiful store such beautiful dresses " . So i went bought one its gorgeous my fiance fell in love with it also . So last week his mom says "so when should i start buying our gowns for the ball " my fiance with a questioning look " OUR GOWNS?" She goes " yes your sis and me , we are going right "? . He says no it's our first ball am only taking Cely . Mom and sister in law " why does she get to go yall aint even married" she can stay we are going . He says well sorry but no . They didn't drop the subject at all its Saturday he gets a call from his grandparents " why are you being so disrespectful to your sister and mom huh so fucking ungrateful you raise them and look how they treat you " . WTF !? But whatever we move she posted it about it on fb of all places lol . But nooooo omg lol they bought gowns !!!!!! THEY BOUGHT THEM LOL , my father in law is stressed out with them he came today and said" they haven't stopped yapping about it " .