My Ds (13 on Friday) reckons this sounds brill (my words, his were a tad more lively!). He says no worries about 16 people its better than 20 ;-)
My thoughts would be as many towels as possible. Bin bags for the wet clothes because teenage boys wont remember.Some form of crips or similar because they will be starving before the burgers will be ready.
Aand heres a thought, do you have any pictures of Ds with his friends? Get them all a printed tshirt with said photo on to wear at the aprty, instead of a crappy party bag or dont they do party bags that at this age and am I about to embarrass myself?
Girls OMG!! Better remember a mirror and a brush then!!
Get Ds to think about teams as well or will the centre sort them out (might be better if they did) less public be on my team as all that stuff has passed at school.
Good luck.DS has now said thats what he wants but we dont have anywhere here plus its horrifically hot (40 plus today) and Ramadan so no eating or drinking in daylight. We have to hold off for a pool party till first weekend in October.