Should this sentence be in the subjunctive. My instincts are tell me know because they have been married already, there is certainty. This is the original sentence. I think it should be "A sus padres no les gustó que Juan se casó con Elena."
The next sentence states, "A sus padres no les gustó, pero Juan casarse con Elena."
Either way, I believe the two were married so the action was fulfilled. However, there is the "que" in the first one....what are your thoughts?