I had two ad-libbed moments when I saw it
The first one was during the "I'm not gonna jump on you!!!" section of Scene 2. I couldn't tell you what happened exactly, but when Nathan bent over he had apparently hurt his back. Matthew thus slowly crawled out between Nathan's legs and Nathan walked over to his desk and sighed "8 more monthes"
Also for my performance, Nathan and Matthew cracked up so hard during rule "#1: never put you own money in the show" that Nathan couldn't even speak. He was laughing so hard that at one point he just opened the window and yelled "HEEEEEEEEEEEEEEELLLLLLLLLLLPPPPPP!!!!"
When Nathan seemed to have redeemed his composure, Matthew very sweetly asked, "And rule #2"
To which Nathan answered, just as sweetly, "Who gives a sh*t"
Seems like that was a problem spot for them throughout their run. Would loooove to know THAT inside joke