I saw a user say it and why do we indeed ignore when the tops are way too young for the uke?

People let it slide because they're the top and it is right because doesn't it seem creepy that an 18yo is having seggs with someone over 25+? I think that's a popular manhwa. Another one is that vampire BL where he's dressed up as a high schooler and he gets with this 27yo man. It gives off "she's a 1000yo so it's legal."