Can the flash be turned off? Can the IF flash be seen by humans?

Some cameras have a day/night options where you can choose if you want it active during the day, night, or both.

Also, most IR flashes are a small red glow. Not necessarily a "flash". But an still be seen if one is looking right at it.

The new blackout models have absolutely no flash.

I agree...it depends on the model. Most of them give you an option on taking day or night photos. If you turn off the IR you won't be able to take photos at night. A little advise, if you are not wanting night photos, on most cameras if you change the mode to "video" it will only video during the day time and will take no night photos/videos. Again, this varies by model.

Thanks for the quick feedback.

The real answer is:
Yes your wife can still see the IR flash if you try to set up the camera in your bedroom

Also, most IR flashes are a small red glow.

How long did it take for your black eye to go away?LOL