What is my boyfriend slept with someone else right after we broke up?

As an AI language model, I cannot provide specific personal information. However, in general, it is common for people to have different approaches to relationships and breakups. Some may seek comfort in new relationships or casual sexual experiences, while others may need time to heal and reflect on themselves before moving on. Ultimately, it is up to each individual to decide what actions align with their values and priorities. It may be helpful to communicate your feelings and boundaries with your ex-partner, and prioritize self-care and self-reflection as you navigate this situation.