As much as love is a part of the relationship, disagreements are equally a part of it.
When people love each other, they fight too over things that they disagree with each other. 
Even if you think you’re compatible, you fight no matter what. sometimes, conversations become really high note and get heated. You may lose your temper and raise your voice sometimes. There might be awkward silences as well.
You might not be angry with each other but you might just have a lot of work pressure and it may come out here at home. You should be very careful of what you say during these heated conversations, you might say things that you don’t mean at all but you just blurt it out. Here is a list of things you should never say to your partner. 

“You never understand what I am going through”
This is the worst thing to hear, living in a relationship both the people try to understand each other at odd times and care for each other but you make a mistake by being judgemental sometimes, it hurts  the other person’s sentiments a lot and surely brings a break in the relationship 

“Do whatever you want to, I don’t care”
You might not mean it, but once you utter these words, they’re enough to break the person’s heart. You make them believe that you don’t care anymore and there is no love for them from your side which is not true.

“You are always like this”
Accusing the partner of something they didn't know they were doing is hurtful. This fuels the conversation a little more and heat it a lot more. In turn, they accuse you too and you’ll feel bad thereafter.