Question:
I have 2, 9 month old sisters Felix & Monkey and a 6 month old lad called Midnight from fetching Midnight home they have all got on like a house on fire untill this morning when i heard hissing in the kitchen as far as i know i think Midnight had Monkey pinned in the corner i think he was being a bit to rough with her and she was hissing at him and her hackles were up
Well this happened 5 hours ago and Monkey won't have Midnight near her she keeps hissing at him and if looks could kill when he walks past he will be dead by now i think he must of really hurt her this morning
Will they eventually work this out and be play friends again
They are all spayed and neutered
Sharon and the fur gang
Answer:
This is all speculation on my part.
At 6 mths, Midnight could be starting to assert dominance and tried to mount Monkey. But Monkey's not having any of it, hence the hissing exchanges.
They got into a tussle fight that turned nasty, and he didn't pull his punches and hurt her, so she's seriously ticked off.
Either situation, hopefully they cool off and get friendly again. I'm not sure there's anything you can do to facilitate that, other than to give them treats facing each other.
Hopefully others can give better suggestions, I just thought that your description was so vivid, and the "if looks could kill" comment was so funny.

Answer:
Thankfiuly everything is back to normal now i fed them together and they were fine and they were back to playing with eachother this morning
Sharon and the fur gang