When replying to "child" comments (comments that are reply of another comment), these comments look like they're a reply to main comment. While I intended to keep nested comments in one level, this may look confusing.

Simple solution: In the string "Zeynel replies to X" X can be whomever is being replied to, instead of topic starter. That can require a new database field.

Another solution: Just do nested comments, they'd probably look cleaner.