Silva knew why he claimed to love Ophelia and even took the liberty to track and approach her first just to make her fall in love with him.
He need her because of their bonds, the only way to unlock his other half, the demon half in him was to mate with the girl who he shared a mating bond with, after he was done with that he really did not care if Amelia lived or died he just wanted to awaken his other half so he can surpass Damon and give him a taste of how he treated him for the many years in the past.
Hearing that question from Silva, Damon's heart skipped a beat, he too wanted to know where Amelia is and if possible try and convince her not to leave him but he can't find her cause he did not know and when he finds her he cannot say anything that would trigger the underlying spell in her.