Sadly age does matter - especially when you state that you want something more than just a friendship but a boyfriend. That ventures into the turbulent area of entrapment and many other things - even if you do not hop on any pose balls or start counting which base you get to.
You need to ask yourself do you wish to RP as a child and therefore accept the rules that a child in SL must adhere to - i.e. be childlike and not venture into even boyfriend territory or do you want more? Do you want to bond with someone else, to spend time with them and get closer? If so then I'd suggest you age yourself in order to put everyone around you at ease.
I may be way off the mark but honestly I think anyone with a child or young adult avatar (i.e. under 18) needs to stay well away for interactions that an adult avatar would - yes I know people have boyfriends in school but that's a total different story and people can clearly see both are the same age. If in doubt err on the side of caution in order to avoid causing yourself and those around you problems.