what do i do?

there's a person i used to be best friends with along with some others and we were a pretty small group. ill try to make this short : not too long ago i realized that the person i was friends with was a very good liar and they were manipulating me everyday. i unfriended them but now they found me on twitter and 'apologized' for what they did and said they were going to be a better person (they were the same as always at the end). im only talking to them because im scared that they could make everyone else think i did something horrible, and i want to tell them about it, but at the same time i dont want to bring all of this to them. what do i do?
(i tried to make this short, but if anyone asks i can try to explain things a bit more clear. im sorry)