Hot spot. Time for the cone of shame. Continued licking will make it worse and secondary staph infections are common with hot spots. Keep it clean and dry. Vetericyn spray can help with healing. Or a little organic unrefined coconut oil. Watch for increased redness, oozing, crusting then it's a trip to the vet.
If it doesn't improve with keeping it clean and dry (no licking) then an antibiotic spray and/or steroid may be needed.