A muck ring is the ring of shit that forms around a penis during anal sex. A Felcher is one who felches. Therefore an MRLF is someone that felches and licks the muck ring off of penises
A fucktard that often uses their mouth, tongue, or other associated body parts to inspect or learn about objects and materials that are very clearly hazardous.
Kevin; I just ate out Brittney Spears!
Pink; You're a goddamn licktard, wait isn't she your ex.