Robbie Sullivan is Claire's old boyfriend from high school. He was invited to dinner by Claire's mom Dede, without Dede asking Claire first. At dinner he brought up stories from when Claire and him were dating. Claire thought that her mom was trying to get Robbie and her back together, but she found out that Robbie and Dede were romantically involved with each other. Later Dede also brings him over to her son, Mitchell's house for one of Lily's birthday parties.
Robbie was Claire's boyfriend from high school and they seemed to like each other. But during the times they were dating, Robbie had fantasies about Claire's mother, Dede. When Robbie revealed this to Claire near the end of the episode, she got furious and snapped at him.
When Phil revealed to Robbie that the former was married to Claire, he was quite in shock and Claire was upset that her mother didn't tell Robbie that she is married with three kids, and instead DeDe only told him "Claire was still trying to figure out her life". But Claire's daughters, Haley and Alex seemed to find him cool as Claire felt they were losing respect for her. Luke also seems to like him, thinking he was rich (although not with money).
It is revealed that Robbie was and still is particularly disliked by Jay and Mitchell. They never liked him as Robbie reveals that Jay used to scare the crap out of him and Jay never liked him in the basement with Claire and Mitchell was put in a headlock by Robbie and they used to wrestle.
- In the the original version of "The Incident", Dede mentions Claire's ex-boyfriend Ricky and later in the original version of "Princess Party" Robbie enters the picture. But in the adaptations of these two episodes, this is different: In the former, Ricky is named Babis, but in the latter, Robbie is also called Babis, apparently signifying that there was 1 boyfriend rather than 2. Also, his full name is Babis Karamoutas.