Is there a word to describe the feeling of being willing or happy for someone to fulfill a need that you don't have without negative connotations? [closed]

This is kind of a difficult feeling to verbalize precisely in a single sentence (if you couldn't tell from the title) but I think it will make more sense if I use some examples. I am looking for a better description word or sentence for this specific feeling.

Example 1. Party A is friends with Party B, Party A never feels hungry but when they are invited by Party B they will still eat with them because it makes Party B happy. Party B greatly enjoys eating and feels disheartened by the lack of enthusiasm that Party A has with eating. Party A however does still enjoy spending time with Party B while eating and has no negative feelings towards the act of eating together, even if they have no passion for the act of eating itself. Party A can't think of a word to describe their indifference to hunger but enthusiasm to eat with Party B that doesn't give Party B the impression that their shared activity Party B values is unimportant or a negative experience for Party A.

Example 2. Party A is in a relationship with Party B, Party A is asexual and has no initiative when to comes to engaging in sexual activity with Party B. They have no negative feelings towards sexual activity, in fact they enjoy being able to make Party B happy, but Party B begins to develop the impression that Party A dislikes sex or themselves because they don't have an innate desire to initiate activity themselves. Party A has no physical desire for sexual activity, but can't think of a word to describe their willingness and enthusiasm for sex with Party B that doesn't make Party B feel that Party A is being forced to do something they don't want or have no passion for.

The common factor in both of these cases is that this feeling stems from a lack of a physical need or desire. Like an inability to feel hunger or develop sexual desire. So they don't have a positive or negative opinion of a physical need/desire they have never experienced. But when Party B's enthusiasm for one of these two feelings is not reciprocated, they struggle to view it as anything other than negative, not simply because they feel their need for shared experiences and feelings isn't being met, but because a lack of passion or initiative in a subject involving them can make them feel Party A is apathetic to their feelings.

I want to use the word indifference, but it doesn't feel right. There can be cases where as a result of the lack of desire Party A may legitimately be put off by partaking in these activities. They may feel it is a pain or a waste of time that could be spent doing other things, but at least in the situations outlined above, it is either completely neutral or a positive experience for Party A. But because of the emotion attached to the subject of indifference, using the word indifference becomes inherently negative and any other synonym sounds worse.

This may start to sound like it is blurring into the lines of personal relationship advice, but my question is purely predicated on the idea that this feeling (while likely quite rare) isn't unique and maybe someone has made or created a more concise word or sentence to describe it. The feeling of not having a physical need/desire but being fine or happy to do it with no negative feelings attached if it makes someone else happy. Is there any better way to describe this?

Being polite

In some cultures, food is always offered the minute one walks in the door. It is considered impolite to refuse it. Accepting unwanted food without complaint is usually considered being polite.

I ate because I was being polite.

The same may apply to sex in the minds of some, but I am not sure that this would be a term the partner would like to hear...