The third season of Sons of Anarchy sees the club in pursuit of Jax’s (Charlie Hunnam) kidnapped infant son Abel. Cameron (Jamie McShane), a True IRA member who sold weapons to SAMCRO, kidnapped Abel as revenge for the death of his own son, then brought Able to Ireland — where the Sons of Anarchy Motorcycle Club, Belfast Charter, otherwise known as SAMBEL, operates. The charter was founded in 1987 by three of the Sons’ original First 9 members, including Jax’s father, John Teller (Victor Newmark). During the trip, Jax has an uncomfortable encounter with one of the women adjacent to the club — one that echoes his late father’s choices and also a famous awkward Star Wars moment.
John was married to Gemma (Katey Sagal) at the time but suspected that she and his friend Clay (Ron Perlman) were plotting against him because he wanted to shift the club’s focus and goals. When John was in Belfast, he had a serious affair with Maureen Ashby (Paula Malcomson), who was peripherally involved with the True IRA through her brother Kellan (James Cosmo), a Catholic priest who had been close with John, and her cousins Michael (Kevin Chapman) and Cameron, mentioned above.
The affair resulted in Maureen giving birth to a daughter, Trinity (Zoe Boyle), though she didn’t tell her John’s identity. John took the secret of his Irish daughter to the grave, but Maureen ends up telling Gemma the truth. She suggests that they keep it between themselves, largely for Trinity’s safety, but gives permission for Gemma to tell Jax. Unfortunately, Gemma doesn’t do this quickly enough.
At this point in Sons of Anarchy, Jax and Tara (Maggie Siff) aren’t together; he broke up with her to keep her out of the SAMCRO life and its many complications. When he meets Trinity, there’s a definite interest between them, and she’s already in the MC world, so that isn’t a concern. On the eve of the club members’ return to California, the pair act on their attraction by kissing each other.
At this point, Gemma and Maureen walk in and rush to stop them, telling them the truth about their father, John. They’re understandably embarrassed to realize that they almost hooked up with their own half-sibling. Their mothers are also understandably horrified, but once the truth is out, all is well. Jax and Trinity part on amicable, pointedly platonic terms. Gemma and Maureen also reconcile, at least enough to respect each other. Trinity and Maureen aren’t seen again in the rest of Sons of Anarchy, but it seems like Jax is glad to know his half-sister and isn’t resentful of his father’s second family.
The incestuous near-miss is similar to the famous kiss between Luke (Mark Hamill) and Leia (Carrie Fisher) in The Empire Strikes Back. The circumstances aren’t identical: Luke and Leia are twins who were separately adopted, while Jax and Trinity are half-siblings with different mothers. Leia kisses Luke in part to get a rise out of Han (Harrison Ford), while Jax and Trinity are just acting out of mutual misguided attraction. Luke and Leia also don’t find out they’re related until Return of the Jedi, while Jax and Trinity realize their mistake almost immediately. Both pairs of siblings manage to recover from their awkward encounters, though, and they have no problem shifting their connections from romantic to familial.