So again, we're back to.. help?
Here's the nomount part of the request:
If stile has nomount on, then no one can mount stile.
If stile has nomount OFF, if mounter isn't calypso, there is a script that blocks player:
"What makes you think you can mount another woman's husband? Get out of here before Calypso smites you!"
Of course, the first line is normal, so no need to have something scripted for that. It's the second part that's the issue as this should go off any time someone tries to mount Stile - whether or not Calypso is on, after all she is the all knowing all seeing goddess of the sea that seems to have a jealous streak when it comes to Stile. I've still not tried an act script at this point in time, so that may be the way to go, just not sure.