Boyfriend/ bisexual?

I recently found out my bf has been using my vibrator I left at his house for anal play.. I’ve only used it like once & that was before he started using it. Maybe I’m just being ignorant but could this mean he’s bisexual?? Really confused. When I asked him about him using it (I said it in a very non-judgement-al way) he admitted to it but seemed very embarrassed. I would never wanna make him feel embarrassed so I didn’t question him any further..