Bristle worm question

[Alberta-newb]

I was cleaning up some red turf algae in my tank tonight when I noticed one of the large bristle worms in my tank poke one end out and emit a jet of white fluid! Enough was "spewed" out that my water turned cloudy. Anyone see this behavior before? Trying to put this delicately to not offend..was it spawning either eggs or sperm, ejecting waste or some type of defence? Should I be worried?