Confused and drunk in Tokyo right now. Please help.

I don't know what to think anymore. When I am sober, I am straight. When I am drunk, I am more attracted to muscular men than women. I just want to feel that chest and back up and down all night.My sister again and again through our lives have said that "I should get a boyfriend, because she definitely thinks that would suit me better and we would a much cuter couple than if I had a girlfriend." She is certain I am gay/bisexual, not straight.I am so confused since alcohol is involved. After one glass of vodka/re wine/whatever strong booze I can find I feel that women are not all that interesting to me, but all my 30 year old life I've only had relationships with women, all of which have ended very very quickly after sex. Like, right after sex I have no interest in them whatsoever.Help me, I am worried and confused.