time to bring up an old topic it seems!
I too am also a horny sneezer… never had it before during my teens or anything, but my long term partner has broken something within me and 85% of the time when im getting aroused or thinking dirty thoughts… i sneeze!
im always glad to see others with the same problem, my mrs loves it as she knows my heads in a dirty place… but i hate it as i feel it breaks the mood slightly
side note, i do sometimes also sneeze going from dark places to bright light, might be linked. i very much doubt i will ever go to the docs to admit to them that i sneeze when dirty thoughts are happening.