Is it a jump/break cue or something? Or is that the factory handle to forearm connection?
Looks to me like the joint has been cross threaded - badly, or possible the insert is damaged or the male joint screw bent - it will undoubtedly need to be repaired after it comes apart.
I would take it to a local cue maker or repair guy right away just let them do it. If you don't have one available, spray the joint with WD 40 using the application tube and let it soak in for awhile, then unscrew it by hand. Any use of tools can potentially break out the wood around the joint.
Chris