Discouraging SO from going to the bar

Kassidy
I am the type of girl that would rather stay at home and have a drink before bed or a BBQ and invite friends over for drinks. However, my SO is the type to go to the bar and get drunk. Now, most of his friends would rather just have a bonfire with a few drinks.
My issue isn't the bar... The issue is the bar EVERY weekend he is home and 3-5 times while he is on hitch. I don't mind him going every now and then to have a good time. 
Also, I'm 20... Just a few months from being legal!
So, is there a way that I can discourage him from going to the bar? Even when I'm 21 I don't think I'll like the bar scene just because I don't even like to party at strangers or "friends" houses... 
If anything separates is it will be the bar!