After a while, it becomes a crazy obsessive game just to get a reply, and it may reach a point where the urge to get responses becomes the main focus, overshadowing any real interest in the women on the site.
Of course, there is something seriously wrong if he's doing it secretly and keeping it from you. It might be worth considering that online dating is extremely addictive.
Most men aren't very successful at online dating, which makes it more frustrating and addictive.
It’s more that they aren’t moving along at the same pace you are, so they juggle until they can make up their minds. This will only put him on the defense and he very well may play the blame shifting game as in make you feel like crap for snooping in the first place.
They are pacing the relationship in their own minds to a degree. At this moment, today, right now, you are most likely more invested and farther ahead in this relationship than he is. Managing your emotions is something that you will be glad you did later down the road as opposed to going bat shit crazy on him.
I am not on a dating site, even though it appears I am. So before your analyzing mind goes into overdrive, make sure that he is actually active and doesn’t just have some dormant profile up there.