ARTHUR Gourounlian’s fans have been left in stitches after he shared his “priceless” Elf on the Shelf prank. The RTE star is always going above and beyond for his kids when it comes to festive fun. And this year, Arthur has fully embraced the much-loved Elf on the Shelf tradition with his little ones. The 45-year-old took to Instagram today to give fans a glimpse at…