You show contempt for each other

According to the Gottman Institute, where pioneering psychologists Dr John and Julie Gottman spent nearly 40 years studying marriage, showing contempt is one of the strongest signs your relationship is ending. More than just your choice of insults, contempt can be conveyed by rolling your eyes at your partner, showing disdain in the tone of your voice and mocking their concerns—any of which are enough to shake your partner’s confidence and their very sense of self. Putting it simply, the loss of mutual respect is a nearly insurmountable obstacle in any relationship.
You criticise each other incessantly

When you use criticism as the primary tool to ‘correct’ your partner’s behaviour – and ultimately their personality – it should serve as a red flag that your relationship is in trouble. How can you tell you’re being too critical? Watch for the use of generalisations in your statements, including, “You always,” “You never,” and “This always happens…” These sweeping statements could lead your partner to feel that they’re ‘never’ good enough for you, which could be the beginning of the end for your relationship.
You make irrational comparisons

Hollywood movies have done to our romantic lives what porn has done to our sex lives—namely, giving us unrealistic expectations about love and what it takes to be involved in a loving relationship. The problem with these unattainable ideals, of course, is that they inevitably leave us unfulfilled. Taking this one step further, 21st-century philosopher Alain de Botton points out that it’s hard to accept the existing self when it’s constantly being compared to an unrealistic ideal. If you find yourself often wishing that you had the life, body or sexual prowess of another, it may be time to obtain the services of a good therapist. It could be worth the investment if you’re committed to saving your relationship.