He may feel sad.
And you might think it’s a pity.
Maybe you are even friends.
But you are allowed to be honest.
You are allowed to clearly say:
“I don’t love you.”
Sometimes feelings change.
Maybe you used to be in love.
But you are no longer in love.
That is also ok!
You do not have to do anything that you do not want to do any more.
Maybe your acquaintance is sad or angry.
But he must take what you say into account.
He must accept that your feelings have changed.
Feelings cannot be forced.