Siamesas refers to Siamese twins, meaning conjoined twins. It's a striking and unusual word to find in a song, especially in the context of a breakup.
The artist uses this word metaphorically to describe a relationship that was so intertwined and codependent that separating felt like a death. He sings, "No éramos almas gemelas, eran siamesas y al separarnos morí" (We weren't soulmates, we were Siamese, and when we separated, I died), powerfully conveying the depth of his pain and the inseparable nature of their bond.
Santa RM's "Mi Última Canción De Amor" [My Last Love Song] is a really intense and emotional journey through a breakup. It starts with the artist reflecting on a past relationship, where he felt completely brokenhearted. He talks about writing many sad songs since his partner left, feeling like it was his fault, and even considering suicide.
But then, the song takes a sharp turn! He starts to remember all the times he felt manipulated or lied to. He brings up moments where he gave in to demands, like when he agreed to stop talking to someone, or when he found suspicious messages on her phone and she blamed a friend. He even calls himself an "imbécil" [imbecile] for trusting her so much. The song builds to a really angry and dark place, with the artist expressing a deep hatred and even violent fantasies towards his ex, though he ironically claims he doesn't hold a grudge. It's a powerful and raw expression of betrayal and anger, definitely not your typical sweet love song!