On social media, they either block them or decide not to hang out while you are with your buddies.
He might have fallen out of love with you and be slowly leaving your sphere of influence and, ultimately, your life.
When he needs to make a decision, even one that could change his entire life, he no longer talks to you first.
This could imply that he lost love for you and now doesn't feel comfortable telling you about his troubles.
You don't keep track of your whereabouts or activities throughout the day, dude. This could imply that he is no longer concerned with your whereabouts or current state of affairs.
This could imply that he has already given up on you because he no longer finds enjoyment in being with you.
He no longer makes compromises or sacrifices to improve the relationship, which is another of the top indicators that he no longer loves you.