Found Out My Brother Is Involved in a Major Sin While Studying Abroad – Need Help

Assalamu alaikum, everyone. I’m dealing with a really difficult situation. My brother moved abroad for his studies, and I recently stumbled upon something that left me heartbroken. On social media, he was casually talking about being intimate outside of marriage, even though he later deleted those posts, some comments remained. He mentioned he’s trying to break this pattern but admitted he might slip again. I’m in complete shock and honestly still in denial-maybe he’s just seeking attention? We were raised in a practicing household, so I never imagined he’d fall into this so fast. I haven’t told our parents because I don’t think I can bring myself to, but I desperately want to guide him back. I feel like I’m losing the brother I knew. Any advice on how to approach this wisely and with compassion? Jazakum Allahu khayran.