The reason we haven't seen Heather Rae Young's fiane Tarek el Moussa on Selling Sunset is simply a conflict in networks. Because Tarek is on HGTV, he hasn't been able to be on Netflix. However, Heather told BuzzFeed that everything had been worked out for him to make an appearance on season four.
Heather loved Playboy growing up so it was a dream come true to become a Playboy model. She was Miss February and the December 2010 Playmate.
Heather's also vegan, which you can hear her mention throughout Selling Sunset.