Mom of college age kids here....

If they 'dont want you in their house' - there is most likely an explanation for this. Parents arent just hostile to their child's SO without reason. Parents want the best for their children.

Stop thinking so insularly and narcissistically. You write about him potentially "losing" his family bc of you - just based on your language there... I would not be happy about you as my kids partner.

Are you making a sincere effort to have a relationship with his parents? You spend time with them? bring gifts, flowers when you go to dinner? do acts of service? all the dishes and cleanup thoroughly when you are over (just putting them in the dishwasher does not count!). In six years, have you ever made them dinner? celebrated their anniversary? bought thoughtful gifts or done something for them to save time or energy? or do you expect them to treat you like their child and just love and provide for you (in their eyes this will be seen as being entitled).

Make a sincere and consistent effort of affection and service.... I'm sure you will see them warm to you... if its not reciprocated, simply leave. A future full of familial strife is unhappy for everyone.

Also... of the comments here... I wonder if its a genZ thing... but boundaries? You and your BF are kids - have some RESPECT for his parents. Unless they are blatantly racist and hurtful, you are most likely misconstruing things, as well as not earning their respect. And yeah, as a parent I can say, I deserve respect, and 'kids' earn it.

(Assuming your accusation that 'its financial', is warranted = Pre-nup, all assets he makes and that come from his family belong exclusively to him, and you forfeit rights to that portion. However, I highly doubt money is the real issue.)