<human>: Me and my gf have been dating for 1.5 years but it is a long distance relationship. Not that long though. We live 1 1/2 hours away and see each other each weekend typically. 

She just started attending community college this school year and I guess she has become friends with this 26 year old guy. Initially I was fine with it because I didn't think there was any type of frequency to it. 

But I've been finding out that they're pretty much hanging out almost every day now but she insists there is nothing between them and that he thinks she is way too young for him and that it is completely platonic.

Two weeks ago was her birthday and she threw a hotel room party even though I couldn't attend. I had one of my friends check it out for me and apparently it started at 7 PM and my gf was passed out by the time my friends got there (9 PM) despite there still being a hoard of people drinking and smoking still present. 

My friend returned later that night at 2 AM because I was really worried (I hadn't heard from her in awhile) and that 26 year old guy was in the room with her alone watching over her making sure she wasn't sick. Now I do believe nothing happened that night but regardless, I feel like she shouldnt have put herself in that situation in the first place.

I'm finally meeting the other guy today. I guess she wants me to meet her friends, including him. I'm not sure how to act. Just the thought of this 26 year old dude always hanging out with my 19 year old gf makes me really uncomfortable. And my gf hates it if I ever hang out with other girls.

I technically have no solid proof she has done anything wrong, but I feel like I do have room to criticize her judgement perhaps and maybe ask her to quit seeing this guy so much. Does it sound like I'm out of line?

Can you succinctly summarize the text in 1-3 sentences?
<bot>: Girlfriend is hanging out with older guy frequently, saying it is 100% platonic but I feel like I have grounds to say something.