When you are "burning bridges," you are generally ending a relationship in such as way that it is unlikely to be reparable in the future. This idiomatic expression is frequently doled out as advice against treating others discourteously or behaving in an unprofessional manner because you can encounter those same people at some future point in time. "Burning bridges" is likely to result in an unfavorable endorsement from these individuals, particularly in a job situation. The origins of this saying can be traced to a common story of two different towns linked by a bridge over a river. When a disagreement causes a rift, one group of citizens from one town sets fire to the bridge and therefore makes reconciliation with the other town much more challenging.
The meaning of idioms such as "burning bridges" is often associated with accepted standards of behavior and interpersonal skills. This type of saying is often spoken when you leave a job position under negative circumstances and worsen the situation further by making disagreeable parting remarks to your superior. When you begin applying for new jobs, the chances of receiving a positive recommendation from that superior are generally not high. This same superior may have considerable influence, and this type of situation can often make the process of finding new employment more difficult than if professional behavior had been observed in the first place.
It is also possible to commit the figurative act of "burning bridges" in personal relationships. A bad break-up with a significant other is a frequent situation that can also bring this idiom to mind. While cutting off the chances of repairing the relationship may often feel gratifying in the short term, it can also sometimes take an emotional toll on both parties in the long run. Frequent acts of "burning bridges" in relationships can sometimes lead to increased feelings of loneliness and isolation as well.
While "burning bridges" is often a behavior many people advise against no matter what the situation, this English saying can sometimes also describe the best course of action under some circumstances. You may encounter a job position with such unfavorable conditions that "burning the bridge" renders you better off if you are not associated with the other individuals in that workplace. This case can be especially relevant when applied to employers with known records of unethical and dishonest behavior such as cheating their customers or failing to pay their employees for satisfactory work performed. The same principle can often apply to personal relationships in which one's significant other engages in abusive or criminal behavior.