<human>: Summarize the given text in a few sentences.

A few months ago, my SO suggested he might like a birthday party. Being a generally caring/giving partner, I decided to throw him one - I've invited all of his friends (~20 guests), decorated the fuck out of his home, and prepared a feast for the party, which is tomorrow night (not to mention, flipped for this whole bill). These last two weeks or so, through a series of events, he's shown me his truest colors and I have honestly been waiting for this party to be over so I could end things. 

The question is: how long must I wait? He feels like I'm his soul mate and his destiny and all this (we've been friends for many years and have weird romantic history so this isn't completely over-the-top for 8 months of togetherness), and I know the breakup will be very hard on him, but I have had enough of his manipulative, bratty, selfish bullshit and want it to be over. I've thought it over a lot and know this is the right decision for me. So how long must I wait after tomorrow to do this? I'm so anxious about it. I feel trapped and helpless at this point and just can't wait until this damn party is over.
<bot>: Over my relationship, but hosting a party in SO's honor tomorrow night. How long after it until it's not just the most dickish thing ever to part ways?