Especially by way of an explanation as to why he had bitten AT LEAST 5 children (seriously - and they were only the ones I saw him have a chunk out of while I comforted the friend my DD had taken with her) was that 'oh, this always happens when he gets over-excited'...?!
Well then, love, EITHER don't bring him to soft play AT ALL, or if you do, you trail him round the place rather than sitting with your mates and having a latte...
Fume...