Sospechaba means "I suspected" or "I had a suspicion." It's an interesting word because it introduces an element of doubt and intrigue into the song's narrative.
In the lyrics, the singer uses it to describe a past feeling of unease: "pero yo sospechaba que jugaba con mi cariño" (but I suspected that you were playing with my affection). This word sets up the emotional journey of the song, where initial doubt eventually gives way to certainty and love.
This song is about finally finding true love after a period of uncertainty. The singer talks about waiting for everything to be theirs, but also suspecting that their affection was being played with: "pero yo sospechaba que jugaba con mi cariño" [but I suspected they were playing with my affection]. They couldn't express what was happening, and when they looked at the other person, they wondered about their feelings.
Then, everything changes! The singer describes a surprising kiss that made them discover a new world: "me sorprendí cuando me besaste un mismo nuevo descubrir" [I was surprised when you kissed me, discovering a new world]. Now, they know the love is mutual: "Ahora sé que me quieres ahora sé que te quiero" [Now I know you love me, now I know I love you]. They feel something telling them this love will last forever. Before this person, their life was sad, but now it's filled with joy, and they are openly in love.