Don't settle for me. Come on dude don't settle for me! Trust me I know guys and that look in your eyes means your in love!
— Heather to Greg, "Josh and I Go to Los Angeles!"
Greg and Heather are friends of Rebecca Bunch who for a time briefly dated each other. Heather Davis was her Rebecca's neighbor whom Greg Serrano had pursued romantically before they met. Greg and Heather both connected through a wry, sarcastic sense of humor that they shared. As they continued to date, Heather wanted to start something serious with Greg. Unfortunately he still had unrequited feelings for Rebecca and once Heather figured this out she ended the relationship. Their first appearance together was in the Season One episode "My Mom, Greg's Mom and Josh's Sweet Dance Moves!".
Greg and Heather were both briefly met at Rebecca's housewarming party. They got to know each other better after he invited her to go with him to his step family's annual Christmas dinner. She helped him deal with the issues he had with his mother and not long afterwards they started casually dating. Greg made the relationship more official when he invited her to a beach trip he and his friends were going on. Things hit a snag when Heather wanted them to become exclusive to one another. Greg panicked and briefly asked that they go on a break instead due to a commitment phobia he refused to admit he had. After recognizing his fears he pleaded with Heather to take him back and she decided to give him another chance. With Greg's help Heather got a job at Home Base alongside him. However, upon observing Greg's reactions to Rebecca she realized he was in love be with her. Unwilling to be Greg's second choice, as a test she broke up with him hoping he would decided to stay with her. Greg elected to pursue Rebecca instead which broke Heather's heart. Heather would later admit this to Greg creating awkward tension between them as she refused to quit her job at Home Base.
In October, Heather Davis was invited to a house warming party by her neighbor Rebecca Bunch. While she was there she recorded another acquaintance of Rebecca named Greg Serrano who was dancing with a giant fish. The two would officially meet months later at the Mall. Heather was working there as an elf and Greg was looking for Christmas presents for his step siblings. Heather finagled an invitation to Greg's step family's annual holiday Christmas Eve (Eve) dinner. While they were there Heather helped Greg deal with his issues with his mother. Afterwards Heather kissed Greg and they began dating ("My Mom, Greg's Mom and Josh's Sweet Dance Moves!").
Greg invited her on a eventful beach trip with his crew aboard a party bus Rebecca rented. Although Greg tried to drag her into an argument that erupted between him and Josh Chan Heather chose to distance herself from the drama the ensued ("I'm Going to the Beach with Josh and His Friends!"). Not long afterwards, Greg was later caught off guard when Heather told him she was now serious about thier relationship and wanted them to be exclusive. In a panic he suggested they go on a break but after some personal introspection he got over his commitment issues. After some groveling and an apology to Heather she took him back ("I'm Back at Camp with Josh!").
Wanting to spend more time together, Greg helped Heather get a job at Home Base. Heather observed her boyfriends reactions to a televised trial Rebecca was involved in and had a revelation. She saw the depth of Greg's feelings for Rebecca and confronted Greg about it. Although he denied this repeatedly Heather dumped him refusing to be his second choice (♫ Don't Settle For Me ♫). Surprisingly Heather also encouraged him to go see Rebecca and confess his feelings to her which he did only to find Josh kissing Rebecca ("Josh and I Go to Los Angeles!"). Heather tried to maintain cool facade about their break up but was hurt by Greg choosing Rebecca over her. At work her extremely lethargic attitude was noticed by Chris who pointed this out to Greg.
However, he was completely oblivious to his part in this when he asked Heather what was the matter. In the face of his nonchalance she became furious and admitted she was upset because he broke her heart. She admitted that her telling him to go after Rebecca was a test which he failed. Heather had hoped Greg would choose her instead but accepts now that he just doesn't have those feelings for her. While resigned to this fact Heather told him she would need time to get over it. Eventually she moved on and even tacitly gave her blessing when Rebecca and Greg started seeing each other ("Why Is Josh in a Bad Mood?"). She also even gave Rebecca advice about Greg encouraging her to be honest with him ("Paula Needs to Get Over Josh!").