Gooned myself stupid anticipating for my (F28) birthday present

Had a birthday last week, and among other things I asked my Dom to throw me a gangbang. And they promise they do. This Thursday I have a day off, so the Wednesday evening it is.
I don't know exact crew they got for me, but it is either men I know and slept with or some of my Dom's friends. Have a cottage rented outside the city with some distance from any neighbors.

I am excited and terrified and and can't stop thinking about it and watch a lots of porn, but I am not allowed to cum since Friday, so it really overwhelms my ability to think.

Any advice or hidden pitfalls I should consider?