To party or not to party?

ok i have an event invitation from someone on facebook...
and it's a guy who i met at a party a couple of months ago, of a friend, and the two of them are room mates. we hardly spoke at the party, maybe just were introduced. a few days ago i went to the party of the same friend as before, so his room mate was there again, and i don't think we even said hi to each other. but now MY friend has gone back to his country, for good, and this guy, the room mate has invited me to his birthday party.. he has 207 friends and has invited 37 people, and one of them is me, and the guest list is closed.... this is after adding me on facebook like the night after the party, whcih i also found strange.but why would he invite me? when he hasn't spoken to me? maybe it's an error . should i message him to say hello and see waht happens and work out what he's thinking. but i duno what i'd say. thing is, i would like to go to the party but i think it will be the same crowd of people it has been before

as it has been at the other two parties and since i only knew MY friend at the other two, i'd be an odd ball.... i dont want to turn up and him and his friends be like 'what the heck is she doing here'? what shall i do? shall i message him?> if so what shall i say?

just ask

ask him the reason somehow that why did he invite you when he doesnt know you well?

Talk to him through a message and ask if he invited you by mistake, because youwon't really know anyone now that your friend is alsta la vista. After he responds and if he says yes, say you would love to go, but you don't really know anyone.