Update: He walked back into my room with the phone still to his ear saying he thinks the call dropped, as he handed the phone back to me it was indeed the panel I thought it was but he didn't see it. Sound the all clear.
I appreiciate the jovial posts, took my mind off the cold sweat.
That's a SUPER obvious "I saw nothing" statement. If the call had really dropped/ended, he would've looked at your phone in confusion because he doesn't know how to hang up. He wouldn't walk around holding a silent phone to his ear. He's
pretending that he never took it down from his ear, and that he handed it to you without looking at it.
Your dad knows what's up. Your dad has had sex before, guaranteed (it's how you exist). Your dad most likely had a porn collection when he was younger (if he doesn't
still have one hidden somewhere). Your dad knows that you're a young man and that you're interested in porn, just like he was when he was your age. The only news is that now he knows that you're interested in boobs, which means that now he knows you're not gay. He always thought you weren't gay, but now he knows for sure. Not that there's anything wrong with being gay, it's just a bit of a relief to learn that you're not. He can barely deal with you being straight, so he sure couldn't deal with you being gay. Your porn might be a little creepy, but it's not that far out there. He's aware of things much more extreme than Monster Musume.
Your dad is a little bit shook, but he's willing to pretend this exchange never happened.