There is no universal rule or guarantee that someone will always go back to an ex. Each person's relationships are unique and influenced by various factors, such as personal growth, changing circumstances, and evolving emotions.
It's natural to feel like your four years with your ex should hold more significance than his five months with someone else, especially if they've experienced multiple breakups during that short period. However, the importance of a relationship to someone can vary greatly depending on the individual and their experiences.
People might rekindle past relationships for various reasons, such as nostalgia, familiarity, comfort, or unresolved feelings. Still, there are no absolute guarantees that this will happen, and it's essential to focus on your own well-being and personal growth rather than waiting for someone else to come back.
If you're feeling hurt or uncertain about the situation, it might be beneficial to seek support from friends, family, or even a therapist. Healing from a breakup can take time, and it's crucial to prioritize your own emotional health and happiness. Remember, you deserve to be with someone who values and appreciates you for who you are.