Parents: please don't try and tell me it's different "when they're my own", especially after you've spent the last ten minutes complaining about how hard your life has become now that you've reproduced.
Please don't assume my life is carefree/boring/meaningless because I don't have kids.
Don't tell me "well, you won't be able to do *insert fun thing here* once you and SO have kids!". Are you trying to talk me out of something I wasn't going to do anyways?
If you tell me "must be nice to be able to do that!", I'm going to assume you meant it in a non-passive-aggressive way and say "yes, it's awesome!", give you a big smile, and walk away.
You are not better than me because you reproduced.
If a dating profile says "I'm not interested in dating someone with kids", move on. Don't send a message to the person that includes the phrase "my kids are different!". You're only wasting your time.
Don't make a big scene out of some child having a public meltdown. We all did it at one point or another. Just go on about your day and go home to your quiet, non-childed home.
Don't rant about "irresponsible parents of the human variety", "moos", and various other derogatory terms for parents and children. At least not publicly.
While it's certainly not required, it is NICE to host events where children are welcome IF you are able to do so.
You are not better than someone who has reproduced.