Responses

I think his heart was actually beating faster (or harder) due to his anxiety/anger towards his current situation, but the ML took it as him being accepting of the situation and his rather sly words. After all, it was from the ML’s perspective at the end of the chapter. He looked pleased that the MC was “open” to the idea through acting coy with a shy smile.
Im wondering who's deceiving who here cause I think your hearts already starting to betray you bae