HARM: Harmful thought, words and actions can sure lead to unhealthy relationships. An occasional outbreak during a stressful moment might be considered normal like swearing; i.e. If someone has'nt been raped, battered ( or other sever trauma has occured) by the other party. However harmful, violent actions such as those and repeated verbal negativity is abusive and healthy in relationships or life.
GUISE: Simulated relationships or those under the guise of having a solid, happy relationship are not destined for success, on the whole. Or rather false is as false does, as forest gump might say. Pretending wears thin and doesn't last long.
INDULGENCE: Instant gratification or indulgence of unhealthy behaviors is a sign of trouble. Grabbing illicit drugs or another mate in secrecy is another. Yielding to unhealthy temptations and desires is a pathway to unhealthy relationships.
I believe these and more will help to rescue your relationship watch out for more on my next update.