As most of us have heard before, "We reap what we sow, more than we sow, later than we sow." You will NEVER have to worry about getting revenge or getting what you deserve...everything aligned to your being always keeps track of what is owed to and for you; good and bad.
Simply because karma is unpredictable, do unto others as you would want things possibly done unto your children.
You are your parents karma. You take on the baggage of your lover's karma. If your lover is tied to bad seeds, you run the risk of intertwining soul frequencies to take on and be affected by their karma. The idea of baggage actually includes their past seeds sown. Be careful accepting the responsibility of another's mistakes into your path. Even through a kiss, you are sharing energy...energy is transferable and connects to your frequency. Everything you allow into your personal space is latching onto your internal force field. Good and bad deeds reside within this force field and await the opportunity to be transferred. Guilty by association applies here.
Be careful with heroic measures of trying to erase someone's pain. It is important that a person be whole, making peace with the self, accepting accountability before attempting to endorse the personal space of another individual. Attaching to another human being intimately while still resolving unfinished business is undoubtedly one of the hardest blows to energy because your levels are still being absorbed through past dealings, resulting in exhaustion and demise of newer frequencies attempting to rejuvenate the lack thereof or loss. Postponing the rejuvenation is how repeated patterns happen in people. Meeting new partners with old familiarity. Feeling like you know someone so well who is equally not a healthy as the person in comparison. What's happening is your past frequencies are absorbing like-energies and attracting them to you, causing an intense feeling of comfort being surrounded by things you haven't yet rid yourself of.
Regardless of how detrimental, if unfinished business is not resolved it results in more pain for you and those who attach to you. Karma has no direction of attack and no matching way of distributing in the same way earned... people with bad energy are not necessarily off limits, it is just important to proceed with caution. A person accepting peace within and accountability as the form of making a truce with past mistakes, does not just become clear of still receiving karma for the bad seeds sown. Every act of wrongdoing and good sowing is producing a future harvest that has no expiration date nor a specific timer for ripeness. Karma just is.