Jealousy is a complex, negative emotion that arises from a perceived threat to a valued relationship, often stemming from feelings of insecurity, fear, and a desire for control. Spencer never truly felt jealous cause he knew Kenzie would never do anything to hurt him. The two were secretly together as they had no idea how the rest of the BAU team would react. Emily, JJ, and Penelope had been trying to get her back dating thinking she was single when she in fact was not. So when they went to Dallas and one of the cops was clearly interested in her and the girls egged him on. He kept flirting with her and she was trying be polite cause she has no idea how long they were gonna be in Dallas for the case but it made her feel un easy. The guy Marcus didn't really know what no meant. Spencer was pissed and jealous the others started to take notice that something was wrong with boy genius. Spencer was laying in his hotel room bed they always got ajoining rooms so she could sneak into his room. She walked in sighing. Spencer didn't even look up from his book.