My BIL lived at my house for almost a year, I certainly didn't 'rub off' on him. I could see though how my AV would have loved the opportunity to compare him to me and visa versa, so I tried real hard not to let it.
I was the guy who lost control of his motor skills, never really dried out so wasn't going through wd , much. That's the only comparison I find helpful, between Me drinking and Me sober. I'm not saying you're not , just that I can sense an AV perspective vis a vis a description of how 'bad' your BIL is and perhaps that let the door open a little to even contemplate a trip to the store and toying with the idea of a 'few'. A bigger and better part knows there is really no calculation of benefit that makes it worth it, right ?