Responses
I'm pretty sure this isn't the story you asked for but your description remind me of them https://www.mangago.zone/read-manga/usobuku_kitsune_wa_hana_o_kamu/
hi! i think the book you may have seen is "invite a wolf intro the house", this has the characteristics you mentioned. but it could also be "the beast's bride" or "fox spirit as the best actor"
https://www.mangago.zone/read-manga/invite_a_wolf_into_the_house/
https://www.mangago.zone/read-manga/bakemono_no_hanayome/
https://www.mangago.zone/read-manga/fox_spirit_as_the_best_actor/
I was in a bookstore looking around at the manga section and I found this Bl that I thought was interesting but couldn't buy it at the time so I wanted to see if I could read it online but I don't remeber the name all I know is that the front cover had a dude with long purple hair and pretty much someone who looked similar to Jinshi from the apothecary diaries, the other dude had short white hair and was a fox spirit I would assume? If anyone knows the name please tell me, I'm really wanting to read it!