the thing about alois and ciel is that a lot of their relationship is clouded with worry, fear, pity and guilt. this is all because of alois being a victim of abuse and ciel desperately trying to save his first love from any harm. sadly at such a young age of 15-17, i think a kid would confuse one of these emotions for something much deeper. ciel lived in complete anguish when he was apart from alois merely because he thought the babe would be beaten to death. in a way the two grew to become dependent on one another (and they still are to this day), and we all know that aint good for a relationship.
i think the connection with sebastian is far more real, more natural, and loads healthier. sebastian is older, more put-together, he’s got a good head on his shoulders and he seriously from the bottom of his heart wants the best for ciel. they give and take and argue and make up and communicate. whereas with alois it was way serious. ciel never once fought with him, never laid a finger on him, never purposely hurt him - all out of fear and pity and guilt. alois is so so fragile to ciel even in their current state alois is like this pristine glass figure that’s delicate and priceless and deserves the best in the world - but it’s something he can only try and protect now instead of possess.
so did ciel love alois more? maybe at that time. but it was only due to the ignorance of youth, teenage obsession, the instinct to protect, and the complete emotional overhaul you experience when you meet your first love. other than that i can safely say that ciel is so deep in love with sebastian that it’s the most powerful connection he’s ever felt.