I recall once my significant other was sitting on the couch, looking out of the window. She was daydreaming and completely lost in thought. Which is why she did not hear my sneaking up on her, and was completely surprised when I literally dove-pounced onto her, lifting her up in the air and onto my lap as I slid my fingers up into her super-ticklish armpits. The shriek of horror that she let out, followed by the hysterical giggles was priceless. It was a proper "scream-laugh" and she was so shocked that she could do nothing to defend herself for the entire time. Silent laughter soon followed, as she laid limp in my arms. I totally had her xD it was glorious!
After I let her go, and she regained her composure, the only thing she had to say to herself was a punch on my shoulder. She's such a good sport :wub