Jealous with girlfriend of my boyfriend's brother?

I've been dating my boyfriend for 2 years, everything was good until his bro has a girlfriend. My boyfriend and his bro and their friends live in the same townhouse, and their girlfriend move to live with them, except me cause I have 2 jobs and very busy sometimes. Since they live together, they usually have party, go to casino, go to travel, or doing stuff together (smoking weed, getting drunk...). My boyfriend shares his location with her (girlfriend of his bro) and I found many conversations with her (for fun, for riding her, talking like everyday...) and usually go to eat or do sth fun outside (with or without his bro). They (their girlfriend) are young (20s) have no jobs, live and eat there for free but never m doing household like washing dishes or cleaning house. since my boyfriend and his bro are kind of rich, They buy luxury things for their girlfriend, taking them to Las Vegas, SF for free; thats why they argue all the time but girlfriend never want to break up and they keep coming and living there since they dont have job. Im kind of frustrated because their girlfriend are so lazy and they just live there to have fun around my boyfriend, enjoy luxury things and I feel so outsider. I and my boyfriend's bro never text, while my boyfriend explained because they live in the same place so they have to text and have fun together (he also text with another roommates's girlfriend). I know I can join them, but honestly I dont speak their language, and Im too busy with jobs so I rarely come to my boyfriend place). I know i shouldn't think too much but I don t know how to get rid of this feeling when my boyfriend always being around with girls and text and doing fun thing like this. I talked with boyfriend many times but he said It's his life, if I dont accept just dont be a part of it. I dont want to break up but this feeling and situation really killing me softly
Jealous with girlfriend of my boyfriend's brother?
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