Rob was Will's roommate in Columbia University. In a flashback episode, he had been dating Grace's friend Ellen in college. Shortly after Will came out, Rob was one of the first people he told. Although he seemed shocked, they remained friends after college and Rob serves as Will's accountant.
After finding out Rob and Ellen are going to get married, Grace admits to Will that she and Rob had a one night stand years ago when the couple were having a fight and Grace had just broken up with Danny.
Ellen is Rob's wife who is also Grace's friend from college.
She and Grace were very close that, as Grace recalls whenever they would get into a fight in college, she would make Ellen a tunnel of fudge bundt cake and they would talk things through. Grace also recalls how Ellen supported her when her father was sick, and when she did not get into a Paris program.
Ellen first appears to have red hair. While pregnant, she stops coloring her hair, revealing her brunette roots. She later dyes her hair blonde.
- Grace notes that she is godmother to one of Rob and Ellen's kids, which may be five or six.
- Rob and Ellen were named after producers Rob Lotterstein and Ellen Idelson who were also writing partners who worked on the show.