Is it normal my wife doesn't tell me what turns her on?

very very common. Unfortunately. At least you're asking though, have you tried confiding in her first?

Mine won't either. It's disappointing. You'd think that after two and a half decades, she'd feel comfortable enough to do so.

I always tease her that she must have some really twisted fantasies..

Ohhh... I just read the title and I already thought "That's annoying." I'll tell you what. Don't ask her what she likes, make her tell you what she likes. If you finger her and she bites back a moan. She likes it.

Why don't you try absolutely everything and make a note of the things she doesn't like. I'm available for the threesome test.

Yeah sometimes you just gotta feel her out and bring up things that excites you and just act on them with her giving her a chance to play along. Its not fun if she has to tell you what to do, its like telling someone the storyline of a movie before they watch it. Take control but dont rush, be patient and comfident, let her come out to you once she sees you trying on your own.

Women... they pretty much want you to figure things out on your own. It's like they expect you to read their minds. With all the yapping, nagging, and gossiping they do, you'd think they'd at least tell you what turns them on.