Boyfriend might be bisexual and wants to explore together

My boyfriend of 6 years wants to explore his possible bisexuality. He wants to do this with me. I have no desire to have a threesome as much as he feels this is important to him. Can I get advice and outcome stories from people in or behind similar situations? I don't want any

I'd walk away. He doesn't seem ready for a serious commitment and the folks that I know that have allowed others into their bed....they have never lasted.