Do you think I should tell.

this guy cheated on his girlfriend multiple times with me and lies to her all the time about tons of stuff. and I dont think its right she thinking that he didnt cheat and lie do you think she has a right to know?? should I tell? I feel bad I know.

More than likely, she will see you as a jealous competitor trying to break them up, not as a kind person so interested in her welfare.

More than likely, she'll be right.

yeah you should tell her shes gonna find out anyways nd when she does shes nto gonna be happy about it so yeah you should tell her