>>115474014no
ex-military generally have the right to use their final rank as a personal title, and to wear their dress uniform (not combat uniform) to formal social events like weddings, memorials etc where appropriate, but there is no requirement to use the rank as a personal title or to continue to wear the uniform, and failing to distinguish between active duty and former duty - where it isn't obvious - is generally a criminal offense where it's done with the express intention of obtaining something - money, goods, preferment - by the deception; the 2005 and 2013 Stolen Valor Acts of the United States cover what Billy's dad is doing here
the joke is more than simply "look at this fat useless idiot pretending to be an ex-SEAL", because some ex-SEALs are fat useless idiots as their former comrades will attest; the joke is that ex-SEALs generally don't identify themselves in public as ex-SEALs; it's a classic Whacker tactic - if you're going to steal valor, you steal it by pretending to be someone whose service history can't easily be checked, which means unless you're unlucky enough to try it with someone who can ask around about you, you'll get away with it - some of them can be quite convincing, FOX News even had one on payroll as an expert for a few years, mostly these people just hang around in malls, so that's impressive in a dumb sort of way
it's reasonably common? people claim to be ex-CIA, FBI, NSA, SEALs, green berets, pilots, all kinds of shit; the more convincing ones embellish what little knowledge they have rather than making up a past from whole cloth, so if you were in Iraq for a couple of years as infantry or private security you might come back and claim you were CIA or something
when I was a kid, it was so common for people's dads and granddads to claim to have been at Normandy on D-Day that it seemed like half the survivors of the invasion force must have lived in our little town: people like to bullshit