Should i go and be a apart of his brothers welcome home why did he hide this info from me?

My brother in law are not close my husband and his brother are from colombia My husband definitely puts his brother in head of me and his brother has been very rude to me. He used to always come to my house and speak spanish to my husband and exclude me from the conversation Finally I got sick of it and told him if he wasnt going to speak english in my home he could leave. Well my husband and him are both in the army and this past yr he got deployed to afganistan On mothers day and valentines day he asked his brother and me to watch his kids because he sent money on both ocions for his wife to go to the spa and dinner with friends. He came home for two weeks in the summer and i told him i thought it was rude to ask me to watch kids like he didnt care about me becuz those were my holidays too. Needless to say we dont get along Well recently he called my husband from afganistan and told him his wife is cheating He didnt want me to know and told my husband not to tell me he's going to forgive her I feel very excluded and cant figure out why he would not tell me embarment or because im white there all colombian. My husband said he wants me to go to the welcome home bbq his wife asked my husband to pick him up from the airport which is so messed up. Even though we dont get along I have respect for him defending our country and i would go for my husband but im hurt i was excluded on the secret my husband told me drunk and said i better not say a word! which i wouldnt anyway He said lets just be hypocrites for a day and go act like everything is ok including being nice to her. No of this is hard for me me and my husband are christians and both believe in marriage So we back him up in his decision even though we dont agree My husband and i were cheated on in our first marriages and learned cheaters dont change. We think he should move on because we think she'll do it again and it better to cut losses quicker the kids will get hurt worst later. I mean she doesnt even want to get him from airport. I told my husband i dont want to go to bbq it seems fake I would hang out with his brother alone no problem My husband said then he'll know i told you If you were in my shoes would you go to the bbq and pretend you know nothing.