Riley Wallace is a recurring character in Season 5 of 90210.
Arc
In The Sea Change, when Annie is at physical therapy with Dixon, she encounters Riley when he is telling her that she is treating him like a baby. He then tells her that although Dixon is not in a good condition, he needs to be able to do things on his own, and that it's hard for him to do that when Annie keeps babying him. When Dixon is worried that he will never get better, Annie tells him not to think like that, but Dixon felt like Annie wasn't making things better by telling him that. Annie has a talk with Riley and he tells her that he has a road ahead of him to recover from the accident. Riley tells her the worst thing she can do for Dixon at the moment is to promise him she'll be there for him no matter what, because it’s really not possible even for her to know if she can keep that promise. She feels Riley is simply bitter and asks him to see a therapist, for his problems.
In It's All Fun and Games Dixon tries walking but isn’t too successful. Riley is trying to push Dixon to walk, and Annie sees this and reprimands Riley for it, as she feels he is being too hard on Dixon. Riley tells her that medically Dixon is now fine therefore he should be able to walk again, it’s just that someone needs to push him to do it. Annie is going crazy trying to find Dixon. She ends up asking Riley for help. Riley and Annie conclude that Dixon might be at the Santa Monica pier, as that is where he was going to meet Adrianna, if he wasn't involved in the accident. Riley meets up with Dixon at the pier, and asks Dixon to talk to him. Dixon tells Riley as to what he discovered at the group therapy session. He tells Riley how he wanted to yell at the girl and tell her how her dad ruined his life, but he couldn’t as her father was just trying to look out for the people he loved, by working hard.
Riley says Dixon is going through the similar thing that he went through after his accident, a few years ago. Riley tells Annie, how his fiance left him after his accident, as she could handle him being on a wheelchair. “To my brother you are a hero” she tells Riley. During Hate 2 Love Riley shows up when Colin and Annie were hanging out, because he has come searching for Dixon. Annie says Dixon isn’t home, but Riley decides to wait for him right there. Annie is later seen asking Riley for advice on how a person in a wheelchair is able to make love. Riley jokingly assumes that Annie wants to make love to him, unaware that Annie was asking him on behalf of Adrianna and Dixon. During Navid and Liam's party Riley is seen flirting with Annie and arguing with Colin.
During The Con, Riley apologizes to Annie for his behavior at the launch party. He admits to Annie that he likes her and that is why he got jealous of Colin. Annie says she “appreciates” his honesty, but wants to give her relationship with Colin a chance. Riley later arrives at the convention to inform Annie about Dixon, as she was unreachable on her phone. She tells him about what Colin has done with Max's program and the two end up kissing. In Here Comes Honey Bye Bye, Annie goes to see Riley before learning that he already had his experimental procedure done. They declare their love for each other and kiss. She later calls for Riley and hears that he passed away that afternoon due to a blood clot that traveled to his lungs.
Relationships
At first Annie didn't like Riley and thought he was a jerk. They slowly began to have a liking for each other and began a relationship. They had many fights over their short relationship but they eventually admitted to loving each other. Annie was heartbroken when Riley died.