Good for you! Speaking for engineers' wives everywhere, thank you!
Of course, it's a give-and-take. It's helped me to understand where it's coming from: work-related habituation as opposed to deliberate desire to be a buzz-kill. Now, when he does it, I feel free to call him on it: "Quit bein' an engineer!!!!" A mutual sense of humor never hurts.
"Show me a completely smooth operation and I'll show you someone who's covering mistakes. Real boats rock." -- Frank Herbert