Would you consider this flirting or being friendly?

I am a (straight at least Ithought I was till I fell for my best friend... who is a ) We hang out & talk & txt alot. I have noticed some changes in our friendship over the past few months & would like to know what someone else thinks. Obviously I am to scared to confront her , actually I am trying to work up the nerve. She likes to tease me.There have been alot of times where we are goofing around & she will grab me by the waist. She always touches my arm when we are talking, If I touch her she doesn't back away. One time she had something on her face & I reached up to it & she closed her eyes & smiled... am I imagining this? or something? when we talk, we both smile & laugh all the time. I feel like we have truly bonded .Sometimes when we are texting back & forth there is alot of teasing & comments about how she's taking a HOT bath, or how she doesn't wear pj's when we were talking about bedding, or I look y with whatever I have on, compliments on my jewlrey & clothes. We are not kids we are women this is not a high school thing. I guess sometimes it's just the way things come across. Lately she's been calling me & I like that better so that I hear her voice. Sometimes the tone of her voice changes. If we are in a large group sometimes we just kind of ignore each other, I think we both feel the same way about each other but I am sure she is confused since I am the straight one & wondering how I will react. Could it be she has a crush on me as well? If we are at a party & there is drinking thats a different story... We are always in each others personal space & if we are sitting next to each other she moves closer. Nothing has ever happened. I don't know if I am making more out of this than it is? I don't know how 's flirt or if it even is or if we are just super good friends? Should I just relax & see what happens? I love this lady alot & even if nothing ever happens she will always be the one who stole my heart & Is my true best friend.