My sisters best friend is acting flirty, touchy, showing me her tan lines, & wants mages.. does she like me?

oh lol thesame thing is happening to me at the moment, but im the girl... how it is with me is that i like the flirting and i do like my best friends brother, but i wouldnt want it to go any further than flirting/ texting/playfighting etc. cuz otherwise it wouldbe awkward for me and my friend.. but im sure loads of girls would try to have thier cake and eat it to....but yeah my best friend just means far to much to me to risk it with her brother....if i knew for a fact that she wouldnt find out then i might do something with him...i dunno, this could be how she feels? hope this helps xx