I talked to my parents about it last January as well as two close friends. My friends were fine. They said as long as I'm safe they had no worries. My dad was very accepting of the whole thing. He just told me he loves me and supports whatever I do.
My mom on the other hand was much less accepting. When I was 11, my mom and I had an incident where, while coming off of anti-depressants, she hallucinated and tried to kill me.
Now, I had experimented with diapers in years previous. The event though has been a catalyst for almost every part of who I am today. Unforunately, I do see it as playing a part in my ABDL side. My mom refused to listen to me though and saw it as the sole root cause. She's come to terms with it now and understands that it's more than her. For her own sake, I made sure she doesn't think she played much of a part though. She goes through a lot of emotional pain over the incident already, and I don't want her to live miserably. I love my mom regardless of what happened.
I came out to my parents for two reasons. At the time, I had never controlled a bank account, and my dad was in the process of helping me establish one, meaning I could spend my money privately with no one seeing what I bought. Granted I live with my dad, I wanted him to know in case he found something in my closet.
I was also going through a period of where I needed acceptance. I had stayed away from ABDL activity since I was 13. As I rediscovered it, I wanted to feel loved by someone regardless of it, so I could stop the binge/purge that had hurt me in my young life. I told my mom and dad at the same time because I knew if my mom found out from someone besides me, despite that chance being small, my mom would be more freaked out as well as thinking I don't trust her.
While the analogy for parents telling kids is funny, the analogy doesn't share the root cause I had mentioned. Parents don't need acceptance as much as a child who is confused and afraid. If you need a support group outside of these communities, meaning forums, I suggest telling someone close in your family who loves you unconditionally. At the time, I never expected to come to these type of forums because of security reasons. I know society's opinion of the fetish isn't the best to say the least, and I didn't want to lose a job or something because I posted here. If I didn't have people that loved me regardless of the fetish, I doubt I would have had the courage to come here. You can't make blanket statements about a fetish like our's though. Everyone is different and some might need more acceptance than others.
Hope that helps.