He listens to you carefully while you vividly describe how the chainsaw man saved you from death in the mouth of a demon.

Denji skillfully pretends that he did not participate in this massacre at all and didn't save you. He doesn't know why he does it, but he doesn't want you to find out that the chainsaw man is actually Denji.

“at least you weren't hurt there? Based on your description, you could have gotten hit too.” The guy said, looking at you from under his eyelashes.