[Diarmuid suddenly looks like he's torn between confusion and anger. What has he done to make the blonde think he's just pitying him? Or maybe, who does he need to hurt for making Prompto just assume that of people?]

Prompto, I like you.

[Lets just repeat that for the record, shall we?]

I would never do something just because I pitied you. I hope whoever did that to you in the past got their asses handed to them.

[He doesn't swear much, but right now Diarmuid can find no other way to expression how strongly he feels about that.]