Done, i now have a fully working bot that does like that:
1- waits for a message from the reply Guy
2- when found, replies to it and waits for replies
3- if found a reply to my reply, go back to 2
4- else, after 10 secs without reply, go back to 1

It's in golang, i can send you the code as a private message (are private messages here encrypted?) nostr.fmt.wiz.biz