Have you ever heard the 'your mom' jokes? A derivative of the 'yo mama' jokes... only these are just awful. My husband and I crack jokes on 'your mom' all the time. We don't mean these things towards literally each other's mothers, but they're hilarious to us (we're out there, we know it, we're okay with it, LOL!)
Anyone, one Easter, we were at my parents house for dinner. My husband made a sly comment to my little brother and I on the ham looking like 1/2 a person's fat @ss... We died giggling, and I said 'it's your mom!'... so now we're really cracking up. Well my mom heard me and says 'R., that's a terrible thing to say!!' (so now my husband and brother are practically crying laughing because mom doesn't get it)... So I tried to explain it to her, and my little brother suddenly goes straight faced and says, loudly, 'R., I don't see how that's funny. That's really messed up to say that about Rob's' mom'... (now my husband has practically left the room he's laughing so hard)... I was like 'Benjamin! You know damn well it's a joke'... little sh!t threw me under the bus!! TOTALLY busted my balls. We were dying ;)
Mom still doesn't get it ;)