Bf drinking.

My boyfriend isn't really into drinking. He just turned 18 and is going to Australia this summer to visit family. He can legally drink there and his cousin (26) is big on bars/drinking and wants to take him to a bar and get him drunk. I know my boyfriend doesn't really want to drink that much but he has a strong feeling she's gonna force him to. Personally I reallllly disagree with drinking (a few drinks, sure fine, but not drunk/wasted). Idk why but I'm just really against this plan and don't want him in that kind of environment. I think part of it could be because he'll be half way across the world and his cousin is gonna FORCE him, but also because the last time my dad was at a bar a drunk guy ran him over and almost killed him (probably the main reason I get so tense about this). It seriously concerns me but I really don't know what to do :(( am I overreacting or wrong for feeling this way?