Tom, I don't have the moustache problem (Menopause hasn't gotten that bad .... yet) but I was/probably will again, have problems with the seal right at the edge of my nose/cheeks leaking because I'm smiling when I dive. I do TRY not to smile while underwater, but diving is fun (right up to the fish feeding part). What is O2 lubricant and would it help make a better seal on a non-moustached face too?