Rob was Laura's boyfriend. When Laura met Abby, she started to have an affair with her behind Rob's back, until she discovered that Abby was her childhood imaginary friend brought into existence by her power.
Rob is first seen interrogating Laura about why she hasn't been talking to him or answering his calls. She explains that she thinks she is now a lesbian and likes Abby, however, Rob violently grabs her arm, resulting in Abby beating him up on the ground.
Later, Laura tells Abby to leave her apartment as she realises that Abby is her childhood imaginary friend, and Rob presumably moves back in with her after this. Abby later comes back to Laura's to try and repair their relationship, however, Rob answers the door and doesn't allow Abby inside.
Abby instead climbs through the bathroom window, and in an attempt to prove to Laura that she is real, cuts her arm with a blade. Rob breaks into the bathroom and pulls Abby away from Laura, but in the struggle to push him away, Abby cuts Laura's arm with the blade.
Later on, Rob walks through the estate where he is presumably killed by Scary, a manifestation of Laura's childhood boogeyman.