your "D" would be the factor causing love to die.
When love is there, spontaneously it is exclusive. This unique feeling somehow raises up till one sets it as a trademark - If you love me, don't you dare loving anyone else - which, u know, intends to control the other.
but none can control other's feeling, neither oneself's.
To love, is to appreciate how the other's existence riches one's life. One certainly has love, this passpart, to share something more about the other more than anyone else. But again, love doesn't give one rights stopping the other's growing and changing.
as you mentioned ealier, "even without her/his attention", it reaches an absolute opposite intention, respection has lost, love has been killed.
有言道：“情深不寿，强极则辱。谦谦君子，温润如玉。” I don't mean it can apply to every single case. However, it is really important to leave some space for each other to breathe.
Don't you think so?