I want to have a threesome with my wife and her youngest daughter. I've brought up the fantasy to my wife on time during sex, and she shot it down.

Her reason was, not everyone involved would consent.. Which gives me the impression she would be willing but thinks her daughter wouldn't be.

I've been dropping hints that we should take up home nudism. I figure it'd be a start, and get them used to seeing each other naked. But this doesn't seem to be going anywhere.