Do guys ever grow up?

I am in the Main Street Cafe (free wifi) and I'm watching the Monday regulars. There's a group of old guys that meet here for coffee. It's about 6 of them and they are over 70 years old. One of the guys just left for the bathroom and the others started giggling and deciding what to do to his coffee. They contemplated salt in the coffee, but decided on the more mature thing to do. They poked holes in his coffee cup. Then, he came back to the table and tried not to look at him. He took a sip, but it didn't spill. They were so disappointed. So, are they in 3rd grade?