Not on the radio, but from FSS.

The student is a real estate agent, and I was teaching her how to get a weather briefing. We talked about it, roll played, then actually called. I had the speaker phone on, but she actually did the talking. We got to the altitude part, and she said "below 3,000 square feet." She corrected herself and burst out laughing. After a brief laughing fit, she got herself together.

The briefer had a very stern voice and said something like, "Young lady, flying is very serious business, and there is no room for silliness..."

She and I were looking at each other like "what is his problem?"

Then he stopped, said just kidding, and gave us the briefing. It was pretty good.


My other one was one night at KMEM:
I was with a student. Our mission was night and tower experience, and MEM was slow, so we went to play up there. We were still at cruise speed (100kts in our 172) and on about a 10 mile straight in. MEM TWR cleared us to land, but a minute later said, "N1234, cancel landing clearance, low approach only, I have an airliner to get out."

Well, I could see the airliner at the end of the runway, so I told MEM TWR we could slow down for him if he needed us to. He asked how slow can you give me? I offered 65kts.

He told us to maintain the slowest speed we could. Our groundspeed ended up being 60kts. After the airliner took off, TWR told us "thanks for your help, now... pick it back up"