You're talking about Alto loving Ranka or Alto x Ranka's pair ?
Do not worry, there is still episode 25, and each his own interpretation.
In my POV, after seeing how Sheryl kissed him and how he didn't respond to her kiss, how she didn't want to hear him talking more when he said he knows now people shouldnt' fly alone, as if she knows he is lying to himself if he says " that's why I'm with you" ...... I think the meaning of the scene is pretty straightforward.
People can see whatever they want but the truth is that he was pretty emotionless when she kissed him, but when he was in front of Ranka he let his emotion speak....
Even his own father said " So that's your stage " ?
This is not over like people think it is