prig – a self-righteously moralistic person who behaves as if superior to others.

pig – calling someone a pig is generally an insult, implying they are unpleasant, dirty, greedy, or have other negative traits associated with pigs…the perception of pigs as messy, gluttonous, or rude.
See: hogwash.

Sometimes it’s a comfortable friend pet name – “That’ll do, pig. That’ll do.”

P(r)ig – the one word contains the other

Yes, sometimes I am a prig. And, dropping the “r,” more often I’m just a pig (emphasis on the gluttonous).

I can live with that. Can you?

Now what might have triggered this speculation?