I do.
And I already did with past girlfriends. One of them I discovered she used to talk dirty with a fuckbuddy planning to 'escape' and see him again. The guy was a swat-like cop and she was all into that fetish.
That ocassion I felt hurt, since there wasn't an open relationship or any sort that I have now with my wife (this gf was dead serious about commitment and jealousy, go figure) so within time I broke.
Now, with my wife, she is aware I check upon her stuff and it even excites us both.