Feelings of attraction or having a crush on someone can be a natural human response and are not inherently "wrong" in the sense of being immoral or unethical. However, the situation you described can be complex and potentially problematic due to the family dynamics involved.
Having a crush on a stepbrother or stepsister can lead to complications in the family relationship, especially if those feelings are acted upon or pursued romantically. In many cultures and societies, romantic or sexual relationships between close family members, including step-siblings, are generally frowned upon or even legally prohibited due to concerns about potential power imbalances, conflicts of interest, and the preservation of family unity.
It's essential to recognize and understand the societal norms and boundaries when it comes to familial relationships. If you find yourself experiencing such feelings, it's important to approach the situation with sensitivity and consider seeking guidance from a trusted adult, counselor, or therapist who can help you navigate your emotions and provide appropriate advice based on your specific circumstances.
Remember that healthy relationships are built on mutual respect, trust, and open communication. In situations involving family members, it's crucial to prioritize maintaining a positive and supportive family environment while acknowledging and processing your feelings in a responsible and respectful manner.