What is Social Hand Grenade?
1.
The act of, when out with friends and having a particularly engaging conversation, coming out with a completely inane or otherwise offensive/distasteful/unfunny comment that is so heinous it kills the conversation dead.
Friend 1: "Aww man that's so funny..."
Friend 2: "Yeah, tonight's been really cool."
You: "Hey, aren't spastics funny!?"
All: <silence>