Hard to come up with a succinct title for this question, but a few sentences should clarify:
My partner and I are hosting a relative of my partner for a 2 week visit. There's a reoccurring issue which is escalating. We'll ask the relative if they want to do something we expect they'd enjoy - sometimes activities they specifically voiced interest in - and the relative declines the activity based on reasons why we wouldn't want to do it or why they don't want to put us through the trouble. That's what I mean by offloading their indecision on us under the guise of caring about our preference. If they actually listened to our preference, they wouldn't put the fault or reasons on us for why not to do various activities.
For example, let's say this relative expressed interest in going out to dinner as we plan for the day. We'll agree, but then when it's time to go out to dinner and we discuss where to go or get ready to go, this relative will implore us to stay home - "Oh, you both seem tired, wouldn't you rather stay home?" or "There's no need for us to go out and spend money, we can just stay home and cook, you two don't need to go out of your way for me." We'll patiently confirm we want to go out, and that the issues this relative raises are nonissues for us. We'll ask if they'd prefer to stay in and we can be flexible, but their response is always about us and never about them (e.g. "Oh, I'm fine to go out or to stay in, but we should stay in because you two ___________").
As noted, this has escalated. It occurs in minor events throughout the day, and it can be difficult to carry on in our usual routines or do the activities this relative expressed interest in doing. There is always an excuse about us and avoiding their own preference. We tried patiently accepting this behavior as an indicator of their preference, but then they contradict themselves by noting boredom or suggesting activities (which they'd later resist).
My partner tried to address this to their relative sincerely, pointing out that this behavior is rejecting positive experiences as if it were our fault or preference, but in reality those are often nonissues and it's as if this relative is 'putting words in our mouth' so to speak. They tried to be kind, but had lost their patience with this reoccurring behavior. As has happened when confronting this relative about anything that may be a fault or weakness of theirs, they became very dramatic and portrayed themselves as the victim of my partner's meanness. (They're not an easy personality to work with but are a relative we care about nonetheless.) This has created an uncomfortable situation and maybe an early end to this visit (on the relative's request, not ours - we'd prefer an amicable remainder to their planned stay and enjoying activities together which we all looked forward to). So whether for now or future encounters, I wonder: How to deal with person offloading their indecision on their host under guise of caring for assumptions of the host's preference?
Edit following up on initial answers: Thanks for the replies all. We already tried what was suggested often, which is basically 'calling the bluff' and either not going out if they resist doing so, or go out anyway and invite them along. It mostly works...they'll come enjoy dinner with us, but in the end of the night still follow up with the "I'm only looking out for you" stuff. E.g. if they said "no need to go out, you both are probably tired" then after a satisfying dinner if we yawn they'd say "What did I tell you? You're both so tired, we shouldn't have gone out." That further strains our patience.
After my partner confronted their relative about this behavior, then tried to make peace by going to do the activity with or without the relative but calmly inviting them first. That contributed to this relative dramatically feeling like the victim and wanting to go home (which is an expensive change of flight schedule in this case). So to conclude...seems most agree 'calling their bluff' is the way to go for this type of behavior, but in this situation, there are other issues (overdramatic, feeling like the victim, rash decisions) at play.