My Secret Kink Revealed to My Partner

I'm a grad student and have been in a committed relationship with Sarah for two years now. Everything is going great, but there's one thing I've never told her about before: my secret kink. Last weekend, during a trip to visit my family, I found an old box of toys from when I was younger that included some rather kinky items. One of them was a blindfold and handcuffs. As I touched the handcuffs, I couldn't help but imagine using them with Sarah. She's always been adventurous in bed, so I thought maybe she'd be open to it too. When we got back home, I mustered up my courage and brought up the topic one night over dinner. To my surprise, Sarah was intrigued! We decided to give it a try that weekend. It felt amazing, but afterward, I couldn't help feeling a bit nervous about bringing this kind of play into our relationship long-term. Is it normal for people in committed relationships to have hidden kinks? Should we continue exploring this side of us?