You tell your friend about a person's funny habit and that person shows it right away without knowing. You tell your friend "See!". You are surprised but you were right. What is the verb for that kind of surprise here? Is "amazed" or "amused" appropriate?
If the habit is not funny but bad or sad, what would be the verb for that kind of surprise?
Not exactly surprised and amused, but there is a word for puzzled and amused:
bemused (M-W)
bemuse: to cause (someone) to be confused and often also somewhat amused
Does that work for you?
If the habit is bad or sad, you could be shocked
I suspected Dexter killed people, but I was shocked/appalled/horrified/scandalized when I actually saw it.
If the surprise is very strong and leaves you in shock, you could say "It was astounding, or if you are speechless for a moment, "I was dumbfound". But I can't think of a single word to express surprised and amused at the same time. A phrase, using the words you mentioned, might work.
It was an amusing/pleasant/delightful surprise. I was amusingly/pleasantly/delightfully surprised.
For other kinds of surprise, use other adjectives/adverbs.
