Stab on the dark, but here it goes. I bet Anna makes the first move. Lol duh!
And it will be a 3 girl circus for the boys to watch, followed by a boy line up blowjob, then swapping blowjobs, and then all girl dildo showx followed by the guys dildoing the girls, followed by sex and more blowjob swapping and fingering. After that it gets a bit hazy. We're in new territory with 3 couples. But I'm quite certain we will see the other couples swap sex.
Something to keep an eye on is big tits guy. Last time all he really wanted was to fuck Anna. Perhaps in the mix of an orgy, he might slip it in.