Come on, cut dad some slack. He saw her standing in the entranceway for a few minutes and probably all she said in his presence was “… Okay.” Unless he has a gaydar with the sensitivity set to 11 or his glasses are actually shipping goggles, he’s not gonna figure it out from just that. On the other hand, mom had a lot more info available and noticed all the hints. I’d like to see the parents show up again in a future chapter.
Just giving him a hard time because it's fun imagining him oblivious for the rest of his life
"Honey, I walked in on our daughter and her friend when they were alone earlier"
"oh dear....w-what did you see?"
"oh, I didn't see much but I noticed they were naked, maybe we need a new heating system since they were clinging to each other to exchange body warmth, such a nice friendship, to be able to help each other in a situation like this."