People can see right through a phony.
If you don’t genuinely care for the other person in the relationship it will show in your words and actions. If it’s important for you to build trust with someone, then you should find ways to genuinely care about them.
Examine the relationship to see what it is about the person, or the role they play in your organization, that you appreciate and value.
Focus on those aspects of the relationship in an authentic and genuine way.