She's never been good at that, but she's improved since Paul joined her in Prague (no credit to him). I don't know if she got instruction outside the apartment, or watched some porn. Either way, she does more than just licking quickly like his dick was a Dairy Queen cone.
That said, her cum swallowing has gone the other way. In Russia, when she realized Paul was cumming, she'd make a little squeak sound as she quickly covered the head of his dick with her mouth and took as much into her mouth as she could, then swallowed, wiped her mouth with the back of her hand, and smiled. Little cum went to waste when she was in control of his dick. Nowadays, it's rare that more than a drop or two passes her lips. Much of the time, she just jerks him off and spills the seed wherever. Even though her appearance has matured and improved, she sucks dick like my ex ("ex" for a reason).