but he stops soon because it doesn't look all that credible (izuku walked in on him watching it with a notebook and pen in his hand) and starts researching gay sex properly
katsuki is not naturally good at sex but he will try his damn best to be a sex god for izuku
absolutely love the thought of katsuki being so super traditional and prude in a way
he does not believe in porn—REFUSE to even watch one. when the boys talk about sex he'd recoil in disgust and stomps away
he believe in masturbating to izuku every night though
every dirty thoughts are all about izuku izuku izuku.
the only times he actually watch porn is because he wants to fuck izuku for real
he'd be super analytical about it too... he'd sit on his desk, and study the material like it's a hero fight to be analysed