“You know, if anybody else were driving that thing, I’d be tempted to diagnose a case of SPS compensation.” / “Of what compensation?” / “SPS.” / “I heard what you said,” I told her. “I just don’t know what it means.” / “SPS? Small penis syndrome.” / “Eww,” I said. / “SPS compensation means driving a huge truck or a souped-up car—or shooting giant guns, or acting supermacho—to compensate for a sense of manly inadequacy. Mind you,” she added, “I doubt that Waylon actually suffers from SPS.”
Source: wiktionary