"Hipotéticamente" (Hypothetically) is a sneaky way of asking an ex to come back without actually asking. It starts with a dream: "Ayer soñé con nuestros hijos, con esos que nunca tuvimos" (Yesterday I dreamed about our kids, the ones we never had), taking them to school together, and "Todo era perfecto, hasta que me despertó el reloj" (Everything was perfect until the alarm clock woke me up).
The chorus is the clever part. Every confession is wrapped in "hypothetically": "Hipotéticamente, ¿volverías a mi lado?" (Hypothetically, would you come back to my side?) and "Si te digo que aún te extraño, ¿contestarías 'Yo igual'?" (If I told you I still miss you, would you answer 'Me too'?). Then he backs off straight away: "No me hagas mucho caso, estoy hablando por hablar" (Don't pay me much attention, I'm just talking for the sake of it). Hablar por hablar is a great phrase to learn. My favourite line is "Te pienso solamente a veces, nada más de vez en siempre" (I only think of you sometimes, just every now and always). He bends de vez en cuando (now and then) into de vez en siempre, which gives the game away completely.