your mistake was not deleting a text from any girl RIGHT AWAY.
man, it's crazy, after a while, you just learn to deny her to have any opportunity to start bullshit with you.
don't leave texts undeleted... even if it's nothing crazy like "OMG, is your mother okay from that accident?? hope she's okay!!!"
psycho b!tches would read that text message and interpret it as a booty call and that you went messing around.