Relationship with David Singh
Rob was shown to be very worried for David Singh, as he was badly injured. However, this timeline was erased by Barry Allen. He told Barry that Singh spoke very highly of him, which surprised Barry.
In May 2015, Rob and David went on their honeymoon.
Attending Barry and Iris' wedding
Rob attended Barry and Iris West's wedding as David's plus-one. Suddenly, the ceremony was attacked by Nazis from Earth-X. Rob and David made it to safety, along with the other guests who didn't participate in the fight. Afterwards, his memory of the encounter was presumably erased.
During the Anti-Monitor Crisis, Rob as well as everyone in the multiverse except for the seven Paragons, was killed in an antimatter wave by the Anti-Monitor on December 10, 2019, only to be restored a month later, after the Paragons and the Spectre created a new universe.
Rob believes that David has a hard head.
At some point, his husband David Singh was kidnapped and replaced by a mirror duplicate. When Team Flash learned about Singh's kidnapping, Cecile Horton contacted him to ask if he saw Singh's mirror duplicate.
Rob appears to be fairly health-conscious, since David Singh is constantly mentioning the "improvements" to his diet which Rob has made.
- In an erased timeline, Rob, presumably along with everyone else in Central City, was killed by Vandal Savage using the Staff of Horus in his efforts to kill Carter Hall and Kendra Saunders. However, due to Barry Allen changing the time continuum, this disaster never occurs.
- His last name is currently unknown. If, when he and David Singh got married, decided to take his husband's name, then his last name is Singh, but this is unconfirmed. He could've kept his own last name, but it's unknown if he did or what it is.