Maybe focusing on non-fire moves for now would help. Vulpix are able to learn a pretty nice spread of moves so perhaps until yours can gain a bit more confidence and less fear, try teaching some dark, psychic or ghost type moves.
If you want, I could send a few TMs your way, as a way to make up for the inconvenience.
[Not going to lie, the suggestion has him freak out a bit, but thankfully Cissnei can't see it through text.] No, no, it's fine! I'll get some myself soon, don't worry!!
Text;
Re: Text;
Text;
[... Wonder if that has anything to do with his Vulpix's fear of fire...? Hmm...]
Text;
Text;
Text;
I am sorry your Vulpix has developed such an odd quirk.
But maybe with a bit of time you can help it overcome the fear?
Text;
But you don't have to apologize, it's not your fault. I'm sure Oohirume will be fine.
Text;
If you want, I could send a few TMs your way, as a way to make up for the inconvenience.
Text;
[Not going to lie, the suggestion has him freak out a bit, but thankfully Cissnei can't see it through text.] No, no, it's fine! I'll get some myself soon, don't worry!!
Text;
[Yeah she's totally sending him some TMs for his derpy little fox.]
Text;
Text;
please don't hesitate to ask.
Text;