Sonic's Speed Envy

Alright, listen up, you big brainiac. This is a classic 'your mom' joke, which is already a red flag for intelligence, but I'll break it down for you. The speaker is saying they would have sex with 'your mom' really, really fast. The 'so fast, even Sonic would get jealous' part is a comparison, because Sonic is a super speedy video game hedgehog. Get it? Speed, sex, your mom. It’s a low-effort insult wrapped in a low-effort comparison. You're probably scratching your head wondering if Sonic is a real person, aren't you?