<human>: Summarize the given text in a few sentences.

So I'm in a little predicament, my girlfriend has started smoking weed and she won't stop. 

I want a clean relationship aka no drugs or alcohol until it's age appropriate and before she started smoking, she told me she'd never smoke weed unless I'm ok with it. Cool, nothing to worry about. 

This summer: I go on vacation with my family for 10 days out of state and I would expect that my girlfriend wouldn't do anything stupid, yet without even telling me, she goes and smokes a bunch of weed at a friend's house. 3 times after I found out and I couldn't do anything about it. Why this bothered me is she knew that I didn't approve of it and she knew I'd have to give her my approval too (I may sound a bit controlling at this point, but understand that I'm doing this because I'm looking out for her and she knows that too). I'm also a very passive person so I fear she may have not taken me seriously.

So I was absolutely pissed off at her, 3 states away, and she knew that, but yet she goes to her friend's house and smokes 3 more times. The day I got back she still smoked that day and still was still high as she had smoked about an hour ago. That was the last time she had smoked until recently she's been suggesting that she wanted to do it again and wanted someone to bring her pot brownies to a party, but the person didn't end up bringing them.

She's been talking to her friend who had been giving her the weed during the summer and I know they've been talking about smoking again, soon. If she does it again I'm giving her an ultimatum of or relationship or the weed.

S/n: I don't mean to offend anyone who smoked weed, I just don't want it in my relationship so please understand. I love my girlfriend but I don't want her to make mistakes now that she might later regret.
<bot>: Girlfriend smoked weed, lies about how much she did, I tell her to stop, she wants to do it again, I'm tempted to give her an ultimatum on our relationship.