Still seems like a virgin 🤷🏼‍♀️

My bf and I have been together for over 2 years. I was the first one he had sex with, before me he was a virgin. It’s been 2 years now with the same “routine” when it comes to sex... at night, before bed. In the bed, him on top. When we talk about other positions he gets discouraged. Now that makes me not want to ask to open the boundaries to experience more positions and spots. I understand I have to teach him but I honestly don’t know how without sounding mean. I feel it should come naturally, I was never taught. I need help and advice! 😔