She's such a beautiful, talented slut. It's a joy to watch her perform as a cocksucker. The way she grasps his veiny, engorged cock with her lips, the way she laves him with her eager tongue, expresses both a high level of erotic love and carnal sluttishness. She needs to enthusiastically suck dick and loves to express how much she craves doing it. Being given tasty jizz is just a reward. Becoming a cumslut means one can perform such nasty, naughty, extremely pleasurable acts without shame or inhibition.