The messenger you speak of is called EQIM. It is available
here for download. Unfortunately it requires you to have an active account on EverQuest in order to login to the messenger. I would have suggested getting your boyfriend to give you his name and password and logging into the messenger with that, but I just tested it and you cannot be on messenger and EverQuest at the same time with the same account (one disconnects as soon as the other sends a message). I seems that there is not a way to talk to your boyfriend in game and you will have to use the old fashioned method of talking on the phone. Sorry.