is this weird?

I am a 15 year old boy and i have a best friend who is a girl. we have been friends since i could talk and she is basically part of the family now. we see eachother everyday and she comes round my house nearly every day. we are not attracted to eachother in any way cause she is my best mate, but for the past month we have just been making out on my bed because we are both single and it just seems to pass time. we havent had sex or anything we just kiss. is it weird. she just said one day to me if i was a good kisser, then i kissed her and she said i was good then she started to kiss me and i said what u doing? then she said y not it will be funny. then we carried on from there. we dont love eachother at all though. Strange??