That’s so excellent! He looks SO happy. Of course, he is on drugs, but still.
I have one FIV-positive cat who is now 7, and shows absolutely no symptoms at all. But her brother was also FIV-positive, and he had stomatitis as well, which we could never get under control. The vet’s last option was to do a full mouth extraction, but he did not make it to that surgery. So Nic’s stomatitis could be caused by his FIV. Just keep an eye on him and know that a full-mouth extraction may be necessary at some point. It might not, too.
ETA - no refund necessary! Nic needs some catnip.