Spewing worm

I have been cleaning my tank tonight, then feeding my lobo and all of the sudden this worm stuck about 3 inches of his body out of the rocks and spewed out this milky oily liquid!! At the time my filters and power heads were off so the lobo would get his food, but I have since turned them back on and this guy has done this 3 more times. So far everything in the tank seems ok, but what the heck was that? I have never seen that before.

 

Some kind of worm, letting sperm out into the tank. I've seen videos of bristles doing it, and my dusters do it occasionally.

 

Sounds like it's spawning. No worries!

 

So I have a six line that keeps things in check, but could this mean more could be on the way. Are they asexual?

 

I think they're hermaphrodites. I don't know if they're simultaneous or not, though.