what do u make of this argument? honest answers please, no craziness?

so its 5pm sat, I just got in with my 3 year old son from a trip to the park. n headed home for dinner. my bro who is 30 pops in to see us as usual on sat, and my mum comes in too by 5.30 to c uus. all normal. my mum comes everyday n helps out too.

my son is eating n then jumps up n wants to go n sit on the other side of table near my mum. the chair is squashed in he cant sit there able so unaccessible, its says, "gosh look at this place, its a mess, couldn't u move the table gosh" to me . I got fed up n said no I couldn't I cant move the table every time he decides to jump off , I cant keep moving it around after him for break lunchn dinner,,..she said "oh I don't care". I said u don't care about what? my son.?

then...big mouth bro jumps in nn yells at me...goes nuts n mad shouting..my son is like watching us. I didn't say anything just let him shout. he said im old women (im 35 he is31) n im making a fool of myself. by asking my mum if she doesn't care about my son. he swore at me..f...g n slammed the door n pissed off. now my mum got big **** hump with me. all I wanna do is make sure my son ate proper.he sits n eats most times....is it me?