TL;DR SO asked to go out alone to the cinema (something I consider to be a couples activity) with a bunch of guys I don`t know/trust. Told her no unless she get someone I trust to go with her or I get to know the guys, did I do the right thing or am I being too controlling?

Quick background; we are both teenagers, shes a virgin, its her second serious relationship, we have been good friends for 2 years and have been in a serious relationship for 6 months. We have a stable and healthy relationship.

Just lately shes been having these wants to go out with her (male) friends without me, this week we discussed about it and Im having doubts if I acted in the right way, I dont want to treat her like my property and prohibit her from doing things, but I think her requests are not reasonable. The conversation went not exactly, but something like:

She: I am going to the cinema with John, Michael (a guy who hitted on her while she was in her first relationship last year) and his friends, okay?

Me: No you wont.

She: Why not? They are my friends and I havent seen them in a long time.

Me: Because going to the movies is something couples do, almost no guy is going to the cinema with a girl without hidden intentions, and I don`t know or trust these guys enough to feel comfortable letting you go out alone with them, they are strangers to me.

She: You dont trust me? And Gabriella is coming too! (Gabriela is in our social circle)

Me: Then ask Lucas (Gabriellas boyfriend and my best friend) to go with you, its completely okay that we get to do things separate from each other, but it`s not okay for you to do -datey- things alone with guys I dont trust.

She: Gabriella doesnt want Lucas to go because every time we go out, we go out with you guys and we want to do things alone. I like doing things with you, but I also want to see my friends.

Me: Think about what you want to do, you are only going with me or if you get Lucas or someone I trust to go with you. Also, if you get me to know these guys, and I know that they are nice fellas, then you can hang out with them without me being around, but as of right now I dont trust any one of them.

She: rants Ok.

Am I being too controlling? Shes quite young, 3 years younger than me and a bit innocent so I feel the need to protect her, and I don`t really trust any of these guys, as while she was in her last (first) relationship, one of them was actually hitting on her. I dont want to lock her in the basement and never let her out, though, but I know the effects that bad / fake friendships (in a way that the guy is only faking being her friend to get to fuck her later) can have in a relationship. Also, we are talking about a young girl who goes out 1-2 times a week, and it has been ALWAYS with me for the last 6 months, so I find it normal for her to want to do things alone (I am more active, I go out 4-5 days a week and mostly without her)