Hello 'northernjeepguy',
<< How do I turn off the previously viewed items.>>
This is a common complaint and as yet ebay has not fixed it. Some people may like it so they can refer to an item they have seen earlier, but those people can add things to the Watch List.
A lot of other people do not want the kids to see what gifts the parents may be choosing and so on.
So the best you can do until ebay fixes this gaff is after ever ebay session go to your computer's cache and cookies (temporary internet files) and delete. Cleaning that out will wipe the slate - for that one time.
Next time you are browsing ebay you will have to do it again.
It's really annoying to some users because even if the kids use a different ID, they are still shown images of what the parents are viewing. It makes it inadvisable to shop for others on a shared computer.
Sorry, I wish I could direct you to a "Hide this" button, but there isn't one. 
