Key to the Duchess's Bedchamber

Ferdinand: "I pour it in your bosom--my fixed love..." (3.1.52)

When I first read this line, I had to go back and read it again to make sure it wasn't saying what I thought it was saying. Thankfully, I had read it wrong. Ferdinand is falsely reassuring the Duchess of his unconditional love for her...that there is nothing she could do to lose his love. I thought for a second that there was a startling reference to an act of foreplay in this line. And not long after this,

Ferdinand: You told me
You had got, within these two days, a false key
Into her bedchamber.

Bosola: I have.

Ferdinand: As I would wish.

Bosola: What do you intend to do?

Ferdinand: Can you guess?

Bosola: No

Ferdinand: Do not ask, then.

Yea, Ferdinand. I bet you'd want the key to your sister's bedchamber, you sicko. I can't help but think that Ferdinand definitely sexually desires his sister. I would be extremely shocked if I turned out to be wrong.