When the Line Blurs...

I've been married for five years now, and we've always had a solid relationship. But lately, something's shifted. A new student at my school... let's call him Alex. He’s in his twenties, but still under me as his teacher. There's just something about him that catches my eye... not that I ever act on it. Or do I? One day, we ended up alone during lunch break and there was this moment... a look passed between us. It felt so wrong yet oddly right. We didn't do anything... or did we? When he left the room, part of me wondered if I should've stopped him... but another part wanted more. I don't know what's happening to me. Am I losing my mind? Is this okay? Should I seek help? Can anyone relate?