The title is a squashed-together Argentine command: "Perdámono'" is "perdámonos" with the final s dropped, and it means "let's get lost". That is the whole pitch. YSY A has spent too much time "preso del amor" (a prisoner of love), and now he wants to spend that time getting lost together instead, "yo por vos, vos por mí, de esta farsa vámonos" (me for you, you for me, let's get out of this farce).
The escape is half romantic, half bedroom. There's a sunset, a world outside where "solo hay traición" (there's only betrayal), and then a blunt "hagámo' un pacto sobre el colchón" (let's make a pact on the mattress). He also slips in a goofy line about "perdiendo el colesterol, adelgazando sobre mi flow" (losing cholesterol, slimming down on my flow), which is a bit much and clearly meant to be.
Watch the ending flip. The verse says "de perdernos hay perdón" (there is forgiveness for getting lost), and the outro keeps chanting "no hay perdón" (there is no forgiveness). Also note the rioplatense "vos" for "you" and "beba" (baby), very Buenos Aires.