Namechanged for this.
I held DS's birthday party today. He is 5. The 7yo brother of one of his friends came along too as the mum wanted to stay with the 5yo and had no other childcare. In my view the pair of them caused havoc but perhaps I'm overreacting and it's normal high spirited behaviour.
The two boys arrived at the party and unwrapped DS's present for him as he wasn't going to do it straight away. It was a board game and they got it out and started playing with it and ended up scattering pieces everywhere. I picked up as much as I could while the kids were playing a party game that DH organised, and in the 5 mins between the end of that game and the start of the next the boys had got some coloured chalk from DS's easel (which was in the corner of the party room) and were stamping it into the floor. It's a wooden floor, so it's no big deal to clear up but I wouldn't let my DS get away with that behaviour.
At tea, the 7yo declared he didn't like anything so his mum went into the kitchen and made a sandwich. Meanwhile he was shouting out rude comments to make the other kids laugh and wouldn't stay sat at the table. When I brought out the cake, the 7yo sang "happy birthday to me" and the 5yo sang "happy birthday poobum". After tea they were merely generally riotous until hometime. Their mother didn't intervene at all even though I had to stop the 5yo bashing a china plate against the table and tell the 7yo "we use polite language in our house" right in front of her.
How normal is this for birthday party behaviour? I felt I needed vast quantities of gin to dull the ringing in my ears after those two had left. I'm a bit upset as DS didn't like other people opening his presents (and losing one piece) or singing alternatives to happy birthday but he was quite calm about it at the party - just telling me afterwards he didn't like it.
I know the mother. I see her quit often. Should I mention to her that I found her kids' behaviour quite difficult at DS's party? Or should I let it go and put it down to overexcitement?