Do a virus, malware scan. How much hard drive space do you have remaining? If less than 10 gig it might be time for a new drive, or clean out the old one. If it's an old install you might try CCleaner to clean up the registry. Use that one with care as you can screw up a windows install if you delete the wrong things willy-nilly.
Of course I know from experience. And...... as others suggested, not only should you have your own browser login you should probably have your own personal login to that machine. Then that takes care of all the co-mingling you're worried about. Since you're married I'd have thought you'd enjoy all that mingling. I'm not married and sometimes think I'd enjoy those things......... but then I drink a beer and it fades from my mind.