My 3 year old's spoilt brat behaviour is infuriating! Help!

[becstarlitsea]

Exhibit 1
At the seaside, DH said he'd buy DS an ice-cream 'if you're good' (I know, I know, but we've all done it, haven't we?) DS was good. DH bought him an icecream. DS ate the icecream. Then DS embarked on an epic campaign of naughtiness (including throwing a stone at a baby - I don't use the word 'naughty' lightly). When we remonstrated with him he said 'I know, but you can't reach the icecream out of my tummy now, can you?'

Exhibit 2
I gave him a surprise present (dinosaur figure) because he'd helped me with the laundry and washing up and earned 10 stickers on his sticker chart over the past few days, and he threw it aside saying 'That's a rubbish present, I want another one.' So I gave him a time out and told him that the dinosaur was going to the charity shop and he said 'Well, that's okay, I'll just get more presents tomorrow'. Which he did (from his grandparents) and he smashed one of the presents they gave him straightaway and said 'I don't care' when I pointed out that it was broken when I got back.

He's singing and laughing in time out, and saying 'Well you can't do anything to stop me' when I tell him off and laughing at me and DH. He knows that I would never smack him.

I'm clearing out his toys today and half of them are going to the charity shop (he has too many - no expensive ones, they're mostly from Poundland, but lots of them), and he's not getting any sweets chocolate or icecream from me or DH for a week. Does anyone have any effective strategies for dealing with this? Very grateful for any suggestions!

Or even a tots martial arts class - got a pc through the letter box that they were setting up an under 6s group... (certainly appeared to take them from 3 up)

Thank you! He's very good at playing with peers, will share & take turns (mostly - he's not a saint!). His worst behaviour is usually when he's with DH and I (ie both of us together - he's better for me by myself, and better for DH by himself). I think part of it is that he's trying to get attention every time DH and I give each other some attention. Which isn't great as DH and I have precious little time together as it is.

Great ideas on games and activities. I was thinking of checking out a soccer school. Music lessons are also a great idea. I can't see him doing ballet - when an ad for Angelina Ballerina comes on before his DVD he scoffs 'Go past the girl stuff, Mum!' Your thoughts on tiredness are very apt mistlethrush. Isn't it tricky to get them just tired enough? I pushed too hard today and now DS is spark out on the sofa (which explains why he was being such a little blighter 15 minutes ago - he was obviously too tired).

God but this mum thing is much harder than I thought it would be. I don't think I'm very good at it to be honest.