my best friend, hb10. help

we talk on the phone/text every day pretty much. When we go out, it's like we both know that we can do anything sexual and thats cool with both of us. she makes me look good by coming and hugging me when im talking to some chicks.
we are both really open with each other, i told her about every girl i've dated, farked, or played. yes, she knows im a playa. lately, a lot of my friends tell me to go for it and be her bf. i have thought about it before and always told myself to stop asking every girl that i meet out so i can get some lady friends.
what triggered my attention what the last few messages we sent each other. she said "... i want to romp! ", as in, i wanna party instead of studying.. so i said "my parents are sleeping, you can sneak it ;b" and her reply was "...it will ruin our friendship, i know it will...."
so that showed me that she is actully down but scared to ruin the friendship like she said.

so i made my first move. she left yesterday to mexico for a week. when she comes back, i told her we are going on a "play date", rock-climbing then sushi. she added hiking in it.

the reason i said "play date" is so she doesnt think it's an actual bf/gf date, but rather so she can see what it would be like if she was dating me. thats my logic here. now i know it will be hella fun on that day with her, my one question is, show i go for the kill? at the top of the mountain perhaps?