"Normal human beings are a little more careful about getting involved in business that isn't theirs. I know that sounds bad, but it's just the way it is."
— Dr. Daniel Jackson
Teal'c moves into an apartment outside the base but has difficulty keeping a low profile when he involves himself in the affairs of others in his community, and ends up wanted for murder when his neighbor's abusive boyfriend is killed. Meanwhile, Carter deliberates over whether or not to accept a marriage proposal from Pete.
"Affinity" provides examples of the following tropes:
- Abandoned Warehouse: The Trust operatives hold Daniel and Krista in one.
- Appropriated Appellation: Teal'c's forehead tattoo, which he has previously described as representing "slavery to false gods", becomes a symbolic variant when his skateboarding neighbor paints it on the nose of his board in honor of the positive effect Teal'c had on the community.
- Asshole Victim: Nobody really blames Krista for killing Doug, given that he was an abusive asshole.
- The Bad Guy Wins: The Trust operatives get what they wanted from Daniel and manage to flee the scene before Carter arrives.
- Blackmail: The Trust attempt to blackmail Daniel into translating some Ancient writing for them by claiming to have evidence that will absolve Teal'c of the murder. When that doesn't work, they take a harsher tactic and kidnap both Daniel and Krista, threatening to kill the latter if they don't get what they want.
- Blatant Lies: Teal'c's cover story for the general public is that he's Daniel's research assistant from Mozambique and that his forehead tattoo is a "tribal marking from his homeland".
- Brick Joke: Daniel asks Teal'c if he's tried talking to the dying fern in his apartment, a reference to Carter's admission that she talks to her plants back in season 2.
- Bystander Syndrome: Played rather cynically as Teal'c draws attention to himself by intervening in his neighbors' problems. It makes him a bit of legend in his neighborhood, but Daniel basically warns him that he needs to cut it out if he's going to keep a low profile, since normal human beings generally don't go out of their way to help other people.
- Continuity Nod: Teal'c makes an offhand comment in "Lockdown" that he would be moving into his own place soon; this episode elaborates on that.
- Curb-Stomp Battle: Teal'c vs. three thugs at the beginning of the episode.
- The Dog Bites Back: Krista ends up killing her abusive boyfriend in self-defense after Teal'c teaches her a Jaffa martial art.
- Fantastic Racism: Some members of the Trust take a dim view of Teal'c living among the general public, despite everything he's done for Earth.Jennings: Stargate Command may think it's okay to let an alien roam the streets unsupervised, but I beg to differ.Daniel: Yeah, never mind the fact that he's helped save the Earth more times than I can count.Jennings: He's an alien. Their motives can never be trusted.
- Fourth-Date Marriage: Pete proposes to Carter, despite the fact that they've only been dating for a few months in the show's timeline. She accepts his proposal at the end of the episode.
- Frame-Up: The Trust take advantage of Krista killing her boyfriend and frame Teal'c for the murder in order to give them leverage over Daniel.
- Friend on the Force: An odd example since Carter's connections go much higher than Pete's, but she makes use of his skills as a cop to try and find evidence that might absolve Teal'c.
- Girl of the Week: Teal'c's brief fling with Krista is never really mentioned again.
- Hero-Worshipper: One of the neighborhood kids develops this towards Teal'c.
- Improbable Weapon: Teal'c takes out a mugger by throwing an avocado from a distance of several dozen feet.
- Is It Always Like This?: Pete makes a comment along these lines after helping Carter with the investigation.Pete: So it's normal for the bad guys just to disappear into thin air, right?Carter: Not really. Although now I think about it, it's not the first time it's happened.Pete: Just another day at the office.
- Mars and Venus Gender Contrast: Conversed between Daniel, Teal'c and Carter when Teal'c admits to his confusion over Krista defending her boyfriend, though Carter clearly has her mind on her own issues.Teal'c: I do not understand Krista's behavior.Daniel: Yeah, that's a common problem. Most cultures on Earth recognize there's a significant gap between the experiences of men and women. Among the Masai of East Africa, each man is actually required to wear his wife's clothing for a month as a way of gaining insight into her life.Carter: If only it were that simple.
- The Masquerade Will Kill Your Dating Life: Carter is initially reluctant to accept Pete's proposal for this reason, wondering whether it would be fair to marry him when she's risking her life every time she steps through the gate. O'Neill points out that he is a cop, so it's not like he doesn't understand having a dangerous career.
- Metaphorgotten: The discussion of the Mars and Venus Gender Contrast quickly sends Carter into a rant about how the media pressures single people to pair off that had been brewing ever since Pete proposed.Daniel: How's things?
Carter: Good. We were talking about Teal'c's friend, right?
Daniel: I thought we were. - Nebulous Evil Organization: It's revealed that the members of what was once the rogue NID have now formed an even shadier operation and are calling themselves the Trust.
- Overt Rendezvous: Jennings has Daniel meet him in a public park and proves that he's serious by having a sniper take out his coffee cup.
- Publicly Discussing the Secret: Carter and Pete openly discuss the existence of aliens in a different public park.
- Sexy Discretion Shot: The scene fades out as Teal'c and Krista kiss in their motel room, and the next scene has Teal'c shirtless in the bed.
- Status Quo Is God: Teal'c finally gets his own place after eight years, but ends up moving back into the mountain at the end of the episode after it causes too many problems.
- Training Montage: After Krista sees Teal'c practicing martial arts in the park and asks him to teach her.
- Trouble Entendre: Jennings does this when he gets Daniel to meet him in public, though Daniel doesn't really play along.Jennings: Either you give me the translation now, or I'll be forced to take this to the next level.Daniel: So, beyond kidnapping and murder?
- Who Names Their Kid "Dude"?:Doug: Teal'c? What kind of a crazy name is that?
