Choosin between 2 people

I have 2 guys in my life. 1 is my ex bf n da other is my current. both of them are friends. my ex wants me back in his life. but i luv my current. my ex says he'l start smokin n drinkin if i dnt *** in2 his life again. even if i go back to my ex i wnt b hapy. my present bf is very suportive.he realy loves me. i care for my ex. he's a realy sweet guy. and i dnt want him to spoil his life. nw wat should i do??? stay with my current bf whom i realy luv n he luvs me too. or go with my ex who luvs me but i dnt. n with 3 lives r gona rein. please help me. wat shud i do????