It’s very exclusive and more intimate physically and emotionally than a good friend. That’s my interpretation anyway.

besides you know what). And should it be?

We’re adults here. You can say the word sex on the internet, and yes.

To me, it seems like you may not be the type of person that feels like they need intimacy. If you want it, however, then that should be ok too. That is a major difference (for many) in people who are in relationships, and people who are just good friends. It’s not the sole defining characteristic, no, but a big one none-the-less.

…they just want a one particular friend with benefits

Why can’t it be both though? I think there’s nothing wrong with that, in my mind. I suppose a big consideration would be if you live together or not, or want to/plan to.