It was, indeed, a fun couple of days. Clay and I had a wonderful time at the party on Friday night. We did a role play scene in which we pretended that we'd never met before, and that I was offering him sexual favors in order to get into the party. Some really hot sex came out of that, but the fascinating thing about it was the way we began to re-establish a relationship in that new context (we weren't playing characters, just being ourselves in this imaginary scenario).
Thinking about it afterwards, it actually struck me as completely romantic. He was the one who took things in the direction of asking me things like "what are you into? do you have any partners... would you like another?" throughout the course of the scene. It was a little like falling in love all over again. A little like he was making it clear that, no matter how we'd met, he'd still want to form a partnership with me.
It's kind of amazing to think that, through role play, we can meet for the first time, and fall in love for the first time, as many times as we want.
I also got the chance to talk to, and cuddle with, a really cute switch girl later in the evening. She happens to be one of Clay's housemates. No opinion yet on whether or not anything will come of that, but it'd certainly be fun to play with her some time.

I saw her again, back at their house, when everything was done for the evening. Her room is right across from his. She was changing her shirt, and showed me her brand new nipple piercings.
Clay and I slept soundly, bodies snuggled up against each other. I drove him to work in the morning (he works weekends, bleh), and he bought me breakfast before starting his day. <3
The party on Saturday night was a bit more of a challenge. For once, I wouldn't be his focus, since a couple of his other partners would be there, including one who he doesn't see very often. I wouldn't say that I felt jealous or upset about it per se, but, in the hour or so before it started, I noticed that I was feeling... unsettled.
On top of that, the start to the party was a little awkward. He'd originally asked me to give him a ride to the venue, then told me a half an hour before that he was getting off work early and would just walk and I could meet him there whenever I liked. I went to the venue right away, expecting I'd get there at the same time he did. I messaged him to let him know I'd arrived, and he said that work had kept him until closing after all, so he'd be a few minutes. I took the time to relax my mind, chill out in my car, listen to some music, and remember that he loves me, I love him, and that even if he was paying more attention to other people at the party that wouldn't mean there'd be any reason for me to feel ignored. More than twenty minutes passed, and I was actually getting a little concerned about him. Eventually, someone else I knew showed up, and I went inside with them.
Clay showed up shortly afterwards and Izzy was with him. He mentioned that he and she had run a quick errand. It raised some questions for me. Was the whole thing about leaving work early, then late, really true, or was it just that she'd shown up and he'd decided that he'd rather walk with her than ride with me, and had made something up so that I wouldn't feel ditched?
I thought about asking him, but then decided to just let it be. There was every possibility that the stuff about work HAD been true, and that Izzy showing up had just been a coincidence, or a matter of convenience related to whatever the errand was. Making an issue of it, especially when I actually had liked having the time to myself to relax beforehand, would have just shown a lack of trust and would have been making a mountain out of a molehill. There's also the fact that Izzy is still in a difficult place (for the record, she's doing better lately), and he and I have actually been spending more time together lately than he and she have -- how on earth could I begrudge them a 20-minute walk together? [Edited to add: Really, I just wish he hadn't said he'd be a "few minutes" when he was actually gonna be 20+ minutes. Dear Clay, please learn to be more specific in your communications soon. *sigh* Maybe this is just something I have to learn to live with when it comes to him. There are far, far worse sins, it just happens to be one of my pet peeves.]
As for the party itself, I can say without reservation that he handled it very well, and I didn't feel ignored at all. It helped that there were LOTS of things to do. As kinky parties go, it was actually one of the most fun and dynamic events I've ever been to. I won some... very *interesting* prizes in a raffle.

Clay didn't end up having sex with anyone, so I didn't get to watch what I'm sure would have been some crazyhot porn, alas. He went home with one of his other partners, and I felt absolutely fine about it.