I'm in highschool and I have 3 good friends that are part of a 6 people group.There's 1 guy who is very good with 48 Laws of Power(not my good friend but we know eachother quite well,manipulative person and always gets his way and everyone likes him.)When they ball bust me it's usually about some dumb shit and I can easily dish it back and make them look stupid.But with this guy there's just no fucking way to outwit him because he makes such dumb jokes that's it's stupid.The one thing he always talks about how he's fucking my sister(which he is not) and everyone laughs while I make a comeback but he just sorta grins and sometimes laughs.But I never know what to say about him back.I usually talk about how I'm fucking his mom but noone laughs when I say it to him.

So my question is how do I ball bust this guy because now it's just getting repetitive and annoying and I don't know what to say back.He has one very younger sister,but I don't want to sound like a pedophile.