I'm upset with my longtime gf for doing coke
Did you see her do cocaine?
Yeah, I saw her do it and I felt so disgusted.
I understand why you're upset. Cocaine can be very harmful, and it's fine to not want to be around it. Are you thinking about breaking up with her because of it?
You think I should break up with her, why? She's a decent person.
I'm not saying that you should break up with her if you don't want to. But I am saying that it would be reasonable if you did, because you're not comfortable with her doing drugs. I think you should let her know how her drug use makes you feel.