There was a group of demons that wanted to take you because you were “valuable to the Winchesters”. Sam caught a few demons when they attacked you and killed all but one bringing him back to the bunker and tieing him up he explained the situation to Dean before saying, “i was protecting Flora, i will always protect Flora.”

Dean cut him off walking towards the demon as he spoke to the demon, “you do not come into my town and threaten people i care about. Going after Flora? Bad move. you leave her alone or i’ll rip you to bits.”

Dean then walked around behind the chair the demon was tied to and gripped his shoulders and leaned over to whisper in his ear, “because i do believe in killing the messenger. and you know why?”

Dean moved his arm around the demons neck choking him before continuing, “because it sends a message.”

you then stepped into the room overhearing the conversation.