I hate my boyfriend's bestfriend

I always become super unhappy when he goes to hang out with him I can't help it. My boyfriend's friend is literally the most disgusting boy I've ever met... he treats his girlfriend like shit and has a real "fuck girls feelings" attitude and my boyfriend is peer pressured to smoke weed and drink whenever he goes over to his house.  He even tried getting my boyfriend into cocaine. Otherwise my boyfriend never even thinks about those things let alone does them.  This issue has always caused arguments between us.  His friend gives me really bad vibes what do I do? Do I just keep biting my tongue?