Going to Mexico and spouse issues

So my husbands and I have been having a few issues. My brother in law lives with us and this past week we decided that he was going to buy his own food and detergent because my whole issue was that I have to buy the big bottles of detergent weekly and I didn't think it's fair when he only gives us "50" dollars weekly for FOOD. Any who that is one issue my husband tells me I have something against my brother in law and that I don't get along with his family. Well now this week he came to me with the news that he wanted to go for a longer amount of time to Mexico. We are originally going for a month the month of December now he wants to go two months November and December. He gave me the option of going with him or staying and then leaving in December. But I do feel it's selfish because he just made de decision without asking me he just said I'm going and you can join me if you want basically. I spoke to my mom and I feel it made it worst and made me mad or idk I need advice. Also I feel like everything is toward his parents and since my mom lives in the US he thinks that she don't need anything cause she has everything. Any advice ?