Absolutely! Sexual orientation and the way we choose to identify ourselves are guided by our behaviour, but also by our desires and our attractions. Sexual orientation is self-identified, which means that your identity belongs to you. If you identify as a bisexual person, no one should question you just because you haven’t been in a relationship with someone of the same gender. It is also the case with any other sexual orientation.
Fondation Émergence. Lexique https://www.fondationemergence.org/lexique
Roberts, Ceri (2012). Can someone really be bi if they haven’t slept with a dude?, http://sites.google.com/a/u.northwestern.edu/shape/blog/cansomeonereallybebiiftheyhaventsleptwithadude
Bisexual Resource Centre http://www.biresource.net/talkingaboutbi.shtml