Dreams of engaging with a stranger in a flirty and sexual manner can often reflect your subconscious feelings and desires, particularly regarding your current relationship. In your case, it seems these dreams may be tied to unresolved feelings about your husband's past infidelity.
The presence of the unknown man could symbolize a desire for excitement or emotional fulfillment that you may feel is lacking in your current relationship. Your dream-self's actions might represent a way of processing hurt or betrayal, as well as a desire for revenge or validation.
Your husband’s reactions in the dream—becoming angry and catching you—could symbolize your own feelings of guilt or fear about crossing boundaries. The frustration you experience might reflect a struggle between wanting to explore these feelings and the reality of your emotional commitments.
To gain insight, consider reflecting on your current feelings toward your husband and the trust in your relationship. It may be beneficial to communicate openly with him about any lingering feelings of hurt or insecurity. Additionally, exploring these dreams through journaling or discussing them with a therapist may help you understand your emotions better and work toward healing.