I like to think of it that way too roly, love can be just love and it can be fulfilling just to love.
I do this readily regardless if someone loves me back even a titch. I totally think they can be a primary even if you are not theirs. As long as you don't have expectations that you receive that title in return and keep yourself from being used or hurt because of it, then why not. There is nothing I like more than bestowing love on people without them knowing. Unfortunately I have been used for this trait and have to be very clear that I bestow love on my own terms, rather than theirs. It can get complicated but can be so fullfilling, as you say. I don't regret giving of myself in loving ways for one moment, regardless of the pain I have had in my life.
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