The tolerant factor between two different individuals in a relationship remains quite strong when compared to the tolerant factor those two individuals share with others and obviously, it is all because of being habituated to each other's patterns in love. But, it doesn't mean they both share the same kind of saturation points in tolerating each other. In a relationship, one person may react quickly whereas the other one takes time to think and revert.
So, without knowing each other's extreme points, sometimes we overstep our partner's peace and harmony by taking the factor of leniency and in the end, it results in relationship cracks. Hence, one must know how much is going to be too much for one's partner to deal with or simply how not to drag any situation to an extent where you encourage one's partner to break the relationship off.
Do not expect your partner to react similarly every single time. It is indeed taking your partner for granted. You must understand that before becoming your partner, he/she is an individual. So respect your partner's individuality and self-esteem.
Recognize, realize and accept if you know that there's a mistake from your side. Don't play the victim card and try throwing blame on your partner even though you know you are wrong. That's not love, that's indeed sadism. Just because your partner accepts your mistakes, doesn't give you any right to victimize him for your wrongdoings. You must alter that attitude.
Pulling your partner's legs, joking, and kidding about his/her physical appearance, mental stability, and career qualifications are considered as devaluing a person. Relationships are meant to elevate each other, not demean one's partner.
Of course, some couples are too jovial to entertain each other by picking up faults in their personal and professional life scenarios. You can be in whichever way you like with your partner privately, but in public and especially in front of your family and friends, never try to degrade your partner. Even though you may crack a joke but things may turn grave serious if your partner thinks otherwise. So, don't take chances to disturb your relationship over a mere joke.
Warning or threatening your partner regarding your relationship breakup surely does not have the same result every time. Your partner may feel cautious for the first time, if you do the second time he may try convincing you, the third time she may become offensive, the next time your partner may start ignoring you and if it continues all the time, one day, your partner may lose interest in you and may make things permanently shut between you both. So, you must realize love doesn't work that way.
If you don't maintain a proper work-life balance, your relationship strings may be cut off because a person must provide time and space in a relationship to grow and survive further. If you overlook this aspect, then there's no meaning in having a partner in your life, and sometimes testing too much patience costs your romantic bond.