Dreams about people we know, such as Adam in your case, can often reflect our feelings and thoughts about them or the relationship we have with them. In this dream, Adam's behavior—ditching you for another woman—may symbolize feelings of neglect or abandonment in your waking life, whether related to him or someone else.

The fact that he referred to himself as your brother could indicate a desire for a closer, more familial connection or perhaps a sense of comfort and familiarity that's being overshadowed by his actions. His behavior might also represent a sense of betrayal or disappointment that you fear or have experienced.

Your response in the dream—enjoying time with your friends and doing cartwheels—suggests resilience and the ability to find joy, even when someone else is being inconsiderate. It may indicate that you value your friendships and know how to prioritize your happiness, regardless of others' actions.

Overall, this dream could be a reflection of your feelings about relationships, trust, and your ability to find joy and support in your social circle. It might be worth considering any underlying feelings you have towards Adam or the dynamics of your friendships.