Watch his behaviour with other girls. Does he flirt with them in front of you? Does he get more comfortable with other girls than he is with you? Does he hang around his friends who are girls or male friends more often than with you? He might be trying to tell you something.
Get physical. If he’s thinking about leaving, he won’t want to hug or kiss you as much as he used to. He might demand some space….
Does he tell you he wants a break or space? If he does might be a sign he just wants to mess around with other chicks and wants you to feel special in a way too. He may want you as a friend with benefits, or perhaps he wants to break up but doesn’t have the courage to go all the way.If he is constantly telling you he has to go when you’re on the phone, he’s just making up excuses.
Think about whether he keeps avoiding you. If he stops calling regularly or text messaging you in the middle of the day (if this is something you normally did), that could be a sign.