It sounds like Stephen needs some real raisins!
You might adapt the morning routine by having Stephen "help" Daddy get things ready. Have him carry some small object that he can't break and you can take your tablets with water on your bedside table while he is busy.
It is not that you can't ever take tablets in front of a little child, it is more that when they see you with something they want it. Of course you are right to tell him they are not for children. You will figure things out as you go along and he will be fine about it.
I remember having a doctor kit when I was little and Mom gave me some M&M chocolate candies to be my medicine. That was fine because I needed them to play the game, but it is also a bad idea to tell children that medicine and candy are the same. My older sisters did get into some of Mom's medicine once and they went into the closet and sucked the coating off the tablets then spit them out when they got to the bad taste.
That is another thing not to copy from my family. They were fine and hopefully my Mom learned a lesson from that. Keep in mind that this was a long time ago and they did not have as much public awareness of things like how to store medicine in the home.