Stacey is a woman that Walden dated in Season 10.
Initially Walden dates her, but she does not pay attention to him and was constantly texting. She did not invite him to a party even though they were dating and was oblivious to the feelings of Walden. He later becomes more interested in her attractive and accomplished grandmother, Linda. Linda first turns him down, but they later fall into bed, and Stacey approves of her grandmother making out with the "old guy".
Trivia
Ironically, being a communications major, she wasn't very good at communicating with others.