Literally the only way I knew about her SM was through friends who gave me updates. Like how she went FB official with OM before the D was final. How she was in "family photos" with OM and his kids immediately. How she got engaged. And unengaged, and engaged and unengaged. Blah blah.
I never once went to look for myself. It took a lot of determination, but I did it. I can 100% say I never went to her SM except during the first week after BD. Trust me, you don't want to. It has the potential to really get in your head.
Block him if you have to. But do not go prowling their SM.
Also, it's interesting to note that my XW never stopped looking at my SM. I'd do something and post it to SM and get a scathing text from XW about the post the next day. Later she told me she would look at my SM all the time, even when she was with OM. She always wanted to see what I was doing. I'm glad to say that I became extremely detached and never had the need to engage in that behavior.
Detachment is HARD but necessary for your survival.
Save yourself. Nobody is coming! BD:11/2017 Filed:12/2017 Final: 2/2018