Jackson and Santana Lopez probably have met each other in Jackson's first year at Hogwarts in 1991. They're both in Slytherin house. It is known that the two get along well to each other and share fun jokes about Gryffindor at the Slytherin Dungeon. The two share their the hate from this house as they both team up to bully some annoying Gryff students, as Santana is known as schools biggest bitch.
When Santana comes in a conflict with Gryffindor Alec Tate in 1992, Jackson stoods up for her together with Theo Raeken by telling Alec to back off. The friendship between Santana and Jackson changes when Jackson hungs out with Hufflepuff Brody Hudson, by becoming softer, which Santana doesn't like much.
However, both seems to have intrest in the same sex, since Santana is openly lesbian and Jackson is openly gay, and they both support the relationships with Brody and Brittany. Santana was named the "Deputy Snake" by Jackson and Theo and the Slytherins will have to answer to her if both Theo and Jackson have other duties to attend to and are therefore unavailable.