Actually, this is a GREAT idea! It will also help to dispel misconceptions like the post above.
DL- Diaper Lover. This is someone who quite literally loves wearing diapers. (And yes, you can love inaminate objects). We are inexplicably compelled to wear diapers. Most also use their diapers, but that isn't a requirement. Not to be confused with a fetish, loving diapers is NOT based on sexuality, but can include it (just like any other love). Embracing this part of who we are can be a very big stress reliever. However, attempting to ignore or deny our need for diapers can be a major source of stress. This has also been well known to bring about what is called a binge-purge cycle, which is phychologically detremental to us.
AB- Adult Baby. This is an adult who has baby tendencies or likes. The amount of likes an AB may have can vary widely, from the occasional pacifier use to full age play with mental regression. Being an AB is usually (but not always) a part of our psyches just as being a DL. It's worth noting you can be strictly AB only, or at a verying degree in conjunctionon with being a DL. I should also stress that being AB means we want to BE the baby, never be WITH real babies. There is absolutely noting pedophile-like with being AB, and our community had been well know to police ourselves in that regard.
Diaper Fetish- This one seems to confuse a lot of people. Going strictly be the textbook definition all fetishes are based on sexuality. Not to be concused with a form of love which can include sexuality at times, a diaper fetishst actually needs diapers (or at least needs to be thinking of them) to achieve orgasm. Wearing a diaper will always produce sexual stimulation as well. While some look down on fetishes in general, most any psychologist will tell you fetishes are a health part of a persons life, and should be embraced when appropriate. This does mean keeping your diaper fetish between you and your partner(s) though. Friends and family do not, and should not, be included in or informed of your diaper fetish.
There are many more sub categories to the overall ABDL community, but this is just to cover the basics. Now that we all understand DL, AB, and Fetish, we can look at when and why to tell others. As mentioned for Fetishes, this one most people can agree should only be shared with your partners. How would you like it if your parents or siblings came to you and started talking about their own kinks and fetishes? You probably wouldn't, so please be kind to others and keep it behind your closed bedroom door.
With abdl, this is a much different case though. This is a literal part of who you are. Everyone close to you has a right to know the full you, and you have the right to still be you around those close to you. So then, who is "close to you". Really only you can determine that. It may be someone you don't even like or know well, yet live in the same house with- as in physically close. It might be someone you hardly ever see, yet have a deep emotional bond with- as in emotionally close. Or it may be anywhere in between that.
So hopefully by now you've figured out what abdl and/or fetish means to you, and you've figured out who should know. But what about why they should know, and what benefit is there to them knowing. Lets start by understanding it is never a question of IF they will find out, but WHEN. From their own benefit, you telling them up front will save them from accidentally stumbing on your "diaper stash" or othewise figuring it out you wear diapers. This will save them from jumping to all kinds of misconclusions about you, and will also save them the embarasement and confusion of having to confront you about it. Another big benefit for them is knowing you trust them with this inner most and vulnerable part of yourself.
Your own benefit of telling them is probably more obvious. There's the stress relief of not worring of being found out, as well as not having to keep everything absolutely secret at all costs. Now depending on your situation you may want to still keep things hidden or out of sight, but at least you won't have to worry about keeping it like some dirty little secret any more. Buying your supplies and disposal will be much easier, as well as wearing around them too (discretely of course). And who knows, they may be more open and acccepting of your abdl side too, which could further your relationship with them and bring you both close still.
... I dread to think what would happen if folks found out I was a "sick perverted weirdo" - and a lot of you should know that AB/DLs frequently get labeled as pedophiles by the public.