Fix "You reassure her and open wide for a treat"

Fixed a bad bit of text logic that described the PC as opening wide for the cumpipe.

Was also going to fix a few instances I'd noticed of blind slaves "seeing" things, but as I looked, I discovered a lot of newSlaveIntro assumes the new slave can see without checking canSee(slave) - too much for me to rattle off quickly, and a lot of it rather difficult to replace without either a lot of new writing or just removing a bunch of stuff for blind slaves. Have opened issue #3223 instead.