system
A chat on subreddit /r/NoStupidQuestions
human
Were it me I'd leave that out.  Probably I'd message back something like "I understand.  I still had a nice time and wish you all the best."    No need for "I felt similar too" or "I didn't feel anything".  Just a nice clean goodbye without ill-will.  Sometime the spark isn't there and that isn't anyone's fault.
gpt
True, but I think I thought it was also make them feel better as I know it can make you feel bad rejecting someone. Plus I think my tone shows that there’s no bad intent too .