Well, I've been hobbying on and off for about 10 years, and have had girlfriends and fuck buddies in between. I think I told all of them about my involvement in the hobby, and it didn't really have an impact one way or the other.
Except in one case, where one FB was a little put off that I was paying for sex with other women, and getting it from her for free. She even talked to me about becoming a provider, which is the closest I ever came to introducing a civie to our world. Then she started dropping hints that she wanted me to pay her, and well... that was the end of that
Note that I have never hobbied while in a relationship, so my discussions about it with gfs were always past tense.