Bisexual Boyfriend

My boyfriend of almost a year just came out to me as bisexual and I'm not really sure what to do. He says that it's not gonna change anything and he still prefers girls but I don't really know what to do with this information. I'm completely accepting and fully know it's not a choice but I kind of cant help but look a little differently at both him and our relationship. What should I do and am I a bad person for having these thoughts?