Ds proofing dd's birthday party

[TheArsenicCupCake]

Okay I need all your ideas please

it is dd birthday very soon.. Normally She opts for a special family day out .. Taking a special friend with her. This works out great because you don't have swaythes of bouncey children around ds2..

However.. This year.. Dd wants a real proper party.. And tbh there is no reason why she should not have that..
I'm thinking of a outdoor party in the park type thing.. So ds2 doesn't have to contend with bouncey noisy children in a confined space.. Dd wants a sporty theme.. Which is great..Ds2 really wants to join in..
There will be two adults (+ds1 who is actually helpful ). We have limited it to 15 children ( incase we have to move indoors because of rain)..

It is however getting me a bit wobbly as ds2 could jolly well blow!
So ideas for an ASD/AS proof party please!..

One year our DS (NT) had a 'football party' - a local lad who was fab with the kids basically spent an hour doing training type things on the playing field behind our house (yep, we were lucky that by chance at the time we lived somewhere we could do that). And then they had a couple of fun games at the end and I gave them all a picnic in the garden.
I am suggesting this because if you could find somewhere/someone suitable (tennis, trampoline ...??) DS could perhaps be a helper/organiser for person running things if he wasn't keen on joining in with the sport part (my DS would not cope with that bit), and also if someone else in charge you can concentrate on him if things get difficult knowing DD and friends still getting their activity. Could be worth asking around even if noone advertises such things. We found this guy because he did taster sport sessions for kids in the holidays and just asked if it was something he would consider.
Then take picnics already in bags to hand out so that is one less thing to worry about.
Another year we hired church Hall and Gymbobs did a session (expensive mind you).
Think our kids have been spoilt but I love a party - as they have got older I have run out of ideas though

Oh and we also told everyone it would still be outside even if it did rain so to come dressed accordingly. It was raining at the start but they just thought that was fun (unless DS hates getting wet of course - our DS2 does and if we tried this now would end up taking off his clothes or walking around with trousers rolled up where they got damp!)

Thanks amper.. Sports party sounds great.. We are lucky enough to have a field and park next to the house. Sports halls are out as the the noise will be an issue.. Though ds can cope with rain.
And it would give ds2 a job.
Thanks again