Yes, it looks like Jeff's girlfriend will play the role of Yvan in this latest version, or that she will join a threesome (whether aware or not that she is in a threesome).I'm also thinking it might be reverse ntr with Jeff's girlfriend, where she will watch him have sex with natasha, I'm pretty sure she hasn't really been with jeff sexually because of the curse
What doesn't seem to happen is that Jeff's girlfriend sleeps with Chris. Mainly because it seems like Jeff hasn't had sex with him yet, if that's the case, I don't think the author would have the girl sleep with Chris before she sleeps with Jeff.