Just be honest and communicate. Whatever you want is fine, as long as you are honest with yourself and the other person. It doesn’t matter what gender they are, they will probably be upset, but there is no point in forcing something if it’s not working for you. If it were me, I’d want to know if my partner was interested in the opposite sex.
Breakups are always a hard thing to do for anyone. Keep in mind your partner’s feelings and be honest with them. Let your partner know that you care about them and want what’s best for you and them. They will be supportive the more honest you are with them about your feelings and intentions. If a person is using this as an opportunity to “come out” Planned Parenthood has great resources on how to find support and tips throughout this process. It’s okay to be curious about sexuality, StayTeen also offers LGBTQ Teen dating advice.