Say there's a really drunk girl you're close friends with and she's massively drunk and trying to get into your pants while you're sober. Doing it would be wrong right?
because she is drunk, and not in the right state of mind. If you don't think so, that doesn't matter, because by law you are punishable for rape, and you can kiss your life goodbye at that point. So, it's better to err on the side of caution.
Honestly OP, it depends.
There's a saying, a drunk person's actions are a sober person's thoughts.
You are ultimately responsible for your actions, drunk or sober. The real question is, what kind of consequences would happen from having sex? If she had a boyfriend you could cause a lot of hurt. Maybe she wanted to save herself for the proper moment, etc.
Drunk sex isn't bad, but knowing the consequences will help you make the proper decision.