A patient interface, including a mask assembly and a headgear assembly, provides improved facial sealing and improved ease of use. The mask assembly includes an inflating or ballooning seal. The seal can be secured between two portions of a snap-fit exoskeleton. The headgear assembly connects to the mask assembly with flexible straps during course fitting and with more rigid straps following course fitting. The straps include holes that fit over a tapering post on the mask assembly.