Why do guys string you along as backup plan and say things but don’t mean them?

Anonymous
Had a boyfriend we broke up after 4 months still wanted to be friends, spent time together at least twice had sexual relations. Was making plans stated that we both were not in the right place to date anyone than not a week later he states he is starting and made it official with someone and all plans we made went out the window. So why say not dating or talking to someone to begin with?
Why do guys string you along as backup plan and say things but don’t mean them?
4 Opinion