Excuse you, Senku! Inigo happens to love this sappy stuff! It's his bread and butter! He seems like he's about to protest by saying as much too-- until Senku talks on, and then there's that shoving motion.

So instead Inigo gasps. Like Senku just did the most offensive thing possible. Except not a single moment of it makes it seem like he's actually upset. Instead he's just being dramatic.

"Senku! Are you really threatening to kill me over me innocently expressing my friendship?!"

Nevermind the fact that the fall indeed isn't high enough to kill someone, most likely..

Inigo sniffs. "I-- I didn't know you were this cruel!"