ok look - i've been on the other end of this so just read and use your own judgement:
i had a bf that i really loved... and i had a best friend too who knew how much i loved him.... well, long story short my bf n me broke up but were still really good friends... he called me and kept intouch when i moved... well, he had a crush on my friend n she liked him too but did not tell me this - she lied each time when i asked her if she liked him - she said no... i'd never do that to you... but more or less she ended up with him ..... they both knew i still loved him - he had played mind games too...... bc of them going together he more or less ruined our friendship (my friend n me) and she ruined my friendship w/ him..... if confused more or less it's not a good idea - it could ruin their friendship - do you really want to do that? make sure to consiter that too!!