Adorableness aside, I'm very pleased that she didn't beat the crap out of him for accidentally peeking.
Well, they
are husband and wife, regardless of their discomfort and embarrassment seeing each other in states of undress, and living in a cramped apartment. At least, that's how I thought of it when this happened during the anime. She's not unreasonable, just easily embarrassed.
"His mom made screeching noises never before heard by the likes of man"
The screech his mom made:
Admittedly, I feel like for Nasa's mom, it's probably leaning towards happy screeching, not so much mad or upset. I mean, her boy has someone, after all. Sounds like a joyous thing, even if it's so sudden and such.