Do we have an OK relationship?

Ok so this year I moved to a new high school for my freshman year. This really hot sophomore girl named Lola came over to my spot at lunch and started sitting with me. We started flirting and getting close. We began going to each others houses, and having sleepovers where it’s just the two of us, and hanging out. Technically they’re not dates, but it's always just the two of us, and all the time, she and I cuddle and hug. We’re amazingly close for two teenagers who only met like a three weeks ago. I mean we’ve started hanging out topless a lot. Lola actually goes braless. Within the couple of weeks, it’s become so normal for us to do this that yesterday I found one of her bras in my room. Now, understand, she’s a really blossoming and attractive girl, and she’s gifted with really big and nice boobs. Especially when compared to all the girls in my grade. And since we hang out so much, and see each other naked all the time, I couldn’t help but notice. Once, Lola told me that her breast size was a 34 D. She seemed pretty calm, but she was giggling a little. I was stuttering like hell, and she hugged me and said that that was cute. We were naked at this time, so her warm, full (and quite soft) breasts squished against my bare chest. I couldn’t help but get turned on, and since my penis was pressed against her thigh, she noticed the effect she was having, and she smiled warmly. Lola teases me and flirts with me a lot, telling me that one of these days she's gonna let me feel her up, and stuff like that. Like last week when we were hanging out topless, she caught me checking her out, and she said “Aww, are you staring at my boobs?” And I flirted back, swearing that I was looking at her necklace. Then she said “I better get a bra on before you start drooling.” Her tone was playful, and she seemed to be happy I was looking at her body. Plus, I noticed that she didn’t actually put on a bra after she said that…. When we’re in private, she shows open affection for me. Displaying cleavage, or cuddling with me and hugging me, or whispering in my ear and then kissing me on the cheek or lips. Do we have a healthy and appropriate relationship? Does the age difference matter? Are we together now, or are we just good friends? What does it mean if she told me her bra size? Is it OK for her to expose her chest to me, and let me feel her breasts? Or for us to hang out topless or naked?

Help please.