Well, yes, if you made Jess your lover before doing the massaging event, then you don't have that option.
I recommend to always keep saves at different points of the game, so if you miss something, you wouldn't have to replay everything.
I posted my save right before massaging event on the previous page if you need it.
As for why it's at the bottom of the walkthrough, probably because it's a separate path. There's a Jane path, Jessica's path, and then there's threesome path (maybe it will be expanded to a harem path someday)