My ds turns 2 in March and am planning to have a party for some of his friends at soft play centre. Want to invite cousin's little boy (same age) but wonder whether I should also invite his older brother (6). Was planning only to invite younger one as hoping to keep party fairly small and calm and think older one would be bored and at a bit at a loose end but I don't want to upset anyone. dh thinks it's fine and to be expected given the age gap but not so sure. Any thoughts?