A conversational pipebomb is when someone (usually the guy only kept around out of pity) destroys all momentum of a social interaction with a single phrase or opinion typically awkward, offensive, or ignorant. This usually results in:
1. everybody in the group becoming angry and the once civil conversation devolving into an argument
2. total silence occasionally interrupted with a half hearted attempt at a joke or topic (which is always shot down)
3.everybody leaving
John: Did you guys hear about that shooting recently?
Dave: The one down in Texas?
Steve: YEAH! Really fucked up stuff!
Hunter: Yeah, for sure but I mean those kids were kinda asking for it.
Steve:..... That's a conversational pipebomb if I've ever heard one