We will have to assume that the Final 1, if he is not Kip, will accept her strong initial lust for him in these earlier episodes. The TV Grapevine preview showed the most passionate make out scene so far, complete with some tongue action. Now, I do recall Russ doing a bit of the same in Trista's season, but he was basically forcing it on her. I do not see Jillian pulling away at all here. In fact, she's initiating it.
While I do agree with many posts that state she is more attracted to him than he is with her, he is still getting "lost in the passion". I also can see him being very, VERY hurt when she dumps him for someone else. This may be one reason why so many on these boards want him to be a final 3 reject and instead have Ed and Reid go head-to-head in the finale. Ed, in particular, LOOKS like he would handle rejection better at a later stage of the process. (Of course, we all know still waters run deep and Ed could completely lose it as well.)