<human>: The situation is that I'm a senior in high school and a sophomore friend of mine and I got high and made out a while back. She seemed very mature for her age, but afterwards she admitted to me that she's never kissed someone before. 

It wasn't a big deal really, but I got really paranoid (because I was high) that she would think we were dating and so I explained in detail that I couldn't be in a relationship with anyone at the moment and got all apologetic like I was breaking her heart or something. 

After some clear headed reflection, I realized that I had made a lot of assumptions about how she was feeling and so I asked to talk to her and told her that exactly how I felt about her which is that I only see her as a friend but am still very attracted to her and would be interested in having a casual relationship with her as long as she would be comfortable with that. She said that would be OK. She wasn't super enthusiastic but I think that's just part of her personality. 

So we've hooked up a couple times, gotten naked, but haven't had sex. All along the way I've been trying to talk and set boundaries but she kind of just shrugs it off. She always says she doesn't think sex isn't a big deal, but I remember thinking that too before my first time and it ended up being a big deal.

Everything seems fine on the surface, but I still have a lot of doubts about the situation. I have been very open and honest about my feelings and thoughts, but I worry that she isn't being totally honest with me. I just don't think I could have handled this situation as a virgin sophomore, and in addition to inexperience, she's also going through a difficult time emotionally right now, but I feel that it wouldn't be right of me to decide for her that she can't handle it because we are two very different people.

Could you distill the essence of the text into 1-3 sentences?
<bot>: I have a FWB that I suspect may not be mature enough to handle that kind of relationship but feel like an ass just assuming that.