I'm new to this forum, but I figured I would chime in on this topic, since it has been of great interest to me:
My earliest memory with diapers was around the age of 4. I was still in diapers at night, and my parents left me with a babysitter for an evening while they went out. When she was changing me before bed, she started performing various oral sexual acts on me. I don't remember much, but the sensation of the diaper under me and open is very clear in my memory. The fetish developed quickly after that, and the rest is history. I kinda wish that the lady hadn't done that to me, but I can't undo that, can I? I'm just glad there are other people out there who know what it is like to have this fetish.
And In But Not One, I appreciate your open mindedness. My brother-in-law found some of this content on my computer a number of years ago and it didn't go over so well!
Also, as I am single, I am a little uneasy about disclosing this to a prospective partner, and it helps to know that people who are not DL can be open minded about it.