I'll echo what Archieroni, Trevor and Dogboy said. I'm AB/DL, and the sexual side is intertwined. I can enjoy wearing and wetting a diaper just for the feeling of relaxation, and I find it de-stresses me, but it will usually arouse me as well. Often I've had no desire to fulfill a sexual urge, and I'll wet my pants or diaper just for the fun of it, but even if I just change, the thought of what I've done will stick with me, and I'll end up doing it again so I can reach fulfilment.
When I'm little, it always end with adult play. I don't regress just for the relaxation side of it. I'll go into little mode for the express purpose of wetting my pants, and achieving release.
That's the one aspect of it that makes me feel a bit uncomfortable on a deeper level. I have no sexual feelings for kids. At all. I have 4 kids of my own, and the thought of involving a kid in any way with my fetish angers and disturbs me.
However, I get very excited by being a kid myself. I love the feelings of naughtiness or horror that I experience when my 9-12 year old little gets when he has an accident. It's great to be desperate to pee, but be that distracted kid who puts it off and ends up with wet pants. The same as being little in a diaper. My little is a bed wetter, so he has an excuse to wear, and if he is eating breakfast and watching cartoons in a wet nappy it's no big deal.
I've seen heaps of actual kids with wet pants. The child itself I won't even pay attention to or remember, but the incident itself I will. Last summer I saw a kid of about 11 or so get out of a car at the beach, and he was obviously desperate. He was really holding himself and potty dancing as he waited for his mother and sister to unpack their stuff. I walked past them to the beach, and when I saw them about 5 minutes later walking down the ramp, he had wet his denim shorts. He was trying to keep a towel around himself but it was still obvious. As luck would have it, they chose a spot in front of me, where he took his wet pants off and had a bathing suit on underneath. He quickly ran into the water.
Now I could not describe that boy at all, except to say he was chubby and had dark hair. I have no interest in that child whatsoever. But I have replayed that scene over and over again while in little mode but with me as that child. I mean here is a kid the same age as my little, dressed as my little dresses, having a desperate wet accident in public in front of his mother and sister. A big kid who should be way too old to be wetting himself.
The thought of me being in that position and telling my mum I've wet myself is just so hot for me. But I'm not interested in that actual child himself, just in me being him. But it's such a grey area though. If I tried to explain to someone else that I found the situation exciting but not the characters involved, I doubt that they'd understand.
When my girlfriend and I regress, we will play as any age from 3/4 -13. Sometimes we wear protection, or we may just use our pants. It's a prelude to great sex. But when the sexual time starts, we are both grown ups. There is no way in hell that either of us could stay little when the action starts. That would feel not just wrong, but evil. We have played as 13 year olds who have wet their pants and turned it into a game of "You show me yours and I'll show you mine," but even that was kept innocent with a sense of childish wonder about it. Afterward, when adult time starts, we don't even reference it, although we are both enjoying our own private thoughts about seeing each other diapered or wet.
But we can also enjoy a good old fashioned diapering as adults as well. Just to sit together and watch a movie while wearing, and occasionally say those magic words, "I just wet myself," is amazing.
So I know you don't need to be AB to be a DL, nor does it have to sexually arouse you to use nappies, but it does for me.