Looking for someone to sit on my face and allow some rimming too! Golden Shower, spitting and armpit worship also enjoyed.

You might find a San Diego provider or two advertising there.

to get high from hypoxia by smothering the recipient.  Personally, I don't like face sitting.  Sometimes her nose runs on my balls.

There can be sensual face-sitting and dominant face-sitting  
To me this is more fetish/kink than BDSM unless there is some form of restraint or punishment, but that's just my take. Almost anything can be made BDSM with a crafty mind.

I don't get to do it enough, LOL