Advice on this???

I'm 24 and married to a great guy.. well last year I let my older brother borrow $800 for personal reasons.. well it's not really a big deal to me at all, we make $200,000 a year on combined income.. but my husband is having major issues with it. He is CONSTANTLY hounding me about asking my brother for the money.. and lately he's been bothering my mom (for some reason) about getting my bro to pay it back.. Well my mom has been tired of hearing it, and when she was here last week and my husband brought it up.. my mom completely screamed at him and then left. So now there not talking, probably ever.. My husband says it to teach my brother "financial responsibility" but it's not a big deal to me, I worked it out with my bro to pay it back as he just started a job.. there's a huge rift in my family now.. and I don't know what to do???