Oh dear lord, Rief. Just stop responding to posts by jomarcenter.
Yes, he should have said thank you. He said it and you get mad at him for saying "hehehe"? Come on dude; I like you, but you're taking this "respond negatively to everything jomarcenter does" policy a little far. I also don't see how forgetting to express your gratitude is worse than not being grateful, but you're entitled to your opinions.
Seriously though, stop responding to posts by jomarcenter - he clearly annoys you to an irrational degree. Just add him to your
ignore list and I think both you and he will notice a dramatic improvement in the quality of your RMRK lives.