"There is no higher pleasure...That means a great deal, Bellatrix, from you"

What do toi think Voldy meant when he a dit this? What could be be referring to as the competing "high pleasure"? Torturing people? Something plus lewd/banal, like receiving affection back from Voldy?

I've been meaning to ask this for ages, and have wondered about it ever since lire DH.

Let's ignore Cursed Child momentarily and base it off the original series.

Thoughts and musings?