J.K.
What about renting out a pool for the afternoon. I know when my brother was younger, the pool at Ford Middle School was a favorite to rent out for his bday.
Also, maybe Splitsville??? But not sure if it'll hold a party of that size. The Allen Event Center is always holding events. Maybe look into what's going on over there during that time of year. At my husband's 40th bday party, I took him, some family and a few friends to the Allen American hockey game at the Allen Event Center. But, a hockey game in June won't be an option...but, like I said, there's always something going on over there.
Have you thought about a comedy club? or even just a get-together at your house.