Going out and buying a whole pack of P-Balloons.
Honestly, though, my personal fantasy usually involves inflation as more of an affliction, something that is inflicted by more external forces than myself or my partner. As dubious as it might sound, my ideal inflation method is something more like an “outbreak” of some inflation virus, or like, a freak weather phenomenon that causes P-Balloons or something with similar properties to fall from the sky.
From there I guess I’d be checking the weather LMAO.