age appropriate yaoi

i was just reading a highs school yaoi with a few sex scenes and it was like any other yaoi ive ever read. and later in the story they mentioned that they were 15, and i felt super gross. im also still in highschool and im only 17 but it seems ive never considered that my FAVOURITE type of manga (high school romances) that may have sex scenes, are between minors. i felt pretty stupid lmao but also very gross. and next year when i turn 18 i probably should stop reading them or stick to shounen ai and shoujo.... what are your guys opinions on this??? does it matter?