There could be various reasons why your ex is keeping your stuff even if he has a new girlfriend. Here are some possible explanations:
Sentimental value: Your ex may have an emotional attachment to the items you left behind. They could remind him of the time you spent together or hold sentimental value from significant moments in your relationship.
Unresolved feelings: Your ex might still have unresolved feelings for you, and keeping your stuff could be a way of holding on to the past or hoping for a potential reconciliation in the future.
Indecisiveness: He may be unsure about what to do with your belongings and hasn't taken the time to sort through them or return them.
Avoiding confrontation: Returning your stuff could lead to a meeting or conversation, and your ex may be avoiding that interaction to prevent any discomfort, especially if he's in a new relationship.
Forgetfulness: It's possible that your ex simply forgot about the items or hasn't prioritized returning them.
Guilt or Obligation: He may feel guilty about the breakup or ending the relationship and keeping your stuff could be a way of trying to lessen his feelings of guilt.
Inertia: Sometimes, people hold on to things out of habit or because they don't want to deal with the hassle of returning them.
Nostalgia: The items you left behind may trigger nostalgic feelings, and your ex might not be ready to part with those memories just yet.
It's important to note that everyone's situation is unique, and the reason behind your ex keeping your stuff may vary based on your specific circumstances and the dynamics of your past relationship.
If you want your belongings back and feel comfortable doing so, you can reach out to your ex and ask for them to be returned. Be respectful and understanding, and remember that your ex's actions may not necessarily be a reflection of their current relationship status or feelings for you.