The relationship between the tribrid-doppelgänger, Alexandria Gilbert and human, Matt Donovan.
Alex and Matt dated throughout the majority of high school until Alex broke up with him following her parents' deaths. He remained in love with her and was jealous when she began dating Stefan. Despite his new relationship with Caroline, he never got over Alex. They eventually were able to return to friends and confidants. They're friendship has gone off the path for awhile after he showed Hope, Jax, Nina, and Lily Klaus' journals about the things that he's done. After that Matt has been trying to make Alex forgive him. Eventually she does but their friendship hasn't been the same but she's slowly starting to trust him again.
They are referred to as "Malex" by fans.