He's emotionally unavailable
Someone who's emotionally unavailable is unavailable in every important way. Life gets busy but that's why we prioritise. If you live in uncertainty with communication and don't feel involved in his life because he doesn't invite you into it, you might be setting yourself up for heartache. Ghosting in a relationship is simply not normal.
He doesn't value your feelings
He makes calls you dramatic, needy, too sensitive, or intense when you show emotion or express your feelings. Even when you are insecure, rather than seek understanding, he rushes to criticise or judge. If you feel like your feelings are constantly being invalidated and you're not getting emotional support, it might be a bad sign.
He runs from emotional moments
If he's always down to get physical but flees from emotional intimacy, he is going to break your heart. To be honest, he's already breaking it if he's doing this. He doesn't want to address conflict, avoids deep conversations about the relationship, and you feel like you don't know him and vice versa because opportunities to do so never come.
He has a history
If you understand his past and accept it, that's okay. People change. But believe him if his character continues to match that past. If he has a history of short-lived relationships or casual relationships, and they act like they aren't serious with you, it is likely who they are.
You carry the relationship
You put in the work to make the relationship work while he is passive and reactive. Relationships are partnerships and require give-and-take from both people. If the relationship is one-sided, there's little hope it will get better.
Relationships take two people willing to work together, physically, emotionally, and mentally. If there is poor balance and a failure to fix it, the relationship may be headed for heartbreak.