This manga is meant for entertainment but if you ever get into this type of situation with your bf/gf then PLEASE BREAK UP FOR YOUR OWN SAKE. Also note that a constant obsession like this manga shows is different from someone asking to see your phone.
It annoys me to no end that the switch going to sleep supposedly would have done anything to her save file. The game didn't even close at the time. You just turn it back on and you're at the same exact spot as before.