He isn’t quite sure if the relationship is going to last.
There may be a part of him that is fearful that the relationship won’t last.
In order to ensure that he still has dating options, he starts browsing dating sites so as not to deal with the repercussions of a breakup on his own.
In essence, he may be browsing dating sites as a preemptive move.
Though you may believe that you are in a relationship with him, he may worry that this relationship is precarious at best.
By browsing dating sites, he knows that he can relieve some of the worry that the relationship may not last.
If he were to discover a few dating sites that he likes, he knows that he has a backup plan just in case his relationship with you doesn’t last.
Another reason why he may be browsing dating sites even though you are both in a relationship could be because he may not believe that you are the perfect match for him.
In essence, he may currently be in a relationship with you because he just wants to be with someone and not be alone at this time.
However, he may believe that you are actually not the perfect match for him.
Hence, he may be browsing dating sites in the hopes that he will find the match that meets everything that he wants in a romantic partner.
He may be complacent with being in a relationship with you for now.
However, in browsing dating sites, he may be hoping that he is able to find his true match at some point.
Until then, he will stay in a relationship with you because he doesn’t want to be without a romantic partner.
However, if he were to find that perfect match thanks to browsing dating sites, he just may initiate conversation with her in order to see where it leads.
Another reason why he may be browsing dating sites even though you are both in a relationship could be because he was upset over something that happened between the both of you recently.
It may have been a particular incident or a number of incidents that may have occurred in the past.
The both of you may have had a disagreement.
He may have tried not to make a big deal about it since, but this incident or incidents may have had a profound effect on him as time went on.
This may have planted the seeds of doubt about his relationship with you, thereby making him feel the need to start browsing dating sites.
There may be a part of him that believes that this problem isn’t going to get resolved.
As a result, he starts browsing dating sites because he wants to see if using dating sites would be a proper alternative in finding a relationship.
Another reason why he may be browsing dating sites even though you are both in a relationship could be because he has gotten somewhat bored or complacent in his relationship with you and he is looking for new women to chat with.
He may crave some new interactions in his life.
By browsing dating sites, he may be hoping that he soon finds dating sites that have women that he would enjoy getting into conversations with.
He has told himself that this wouldn’t be cheating.
All he would be doing is merely chatting with these women online.