Love and kindness moves together, you can't carry hate in heart and then be kind...

Kindness should be from within not just an act for the time being, some people do things because others are watching, they just want to play the role because the other person did same...

Just like you said, if you ain't kind you must not expect kindness in return..

Sometimes, people ain't kind but they expect more of it from you..you can't be heartless and expect people to be nice to you..

Just like the legal saying "Nemo dat quod non habet"

You can't give what you don't have, you love and get loved in return (vice-versa)...

Have a great day @sugandhaseth