When you can fall in love with someone of the same gender, but you would never date them. However, you can fall in love with and would date someone of the opposite gender.
A Bellasexual is a dickrider of the YouTube Gacha Life ragebaiter Bellathewolf. Often times, these people are just trolls who do it in order to pack underage people.
Usually they know it's ragebait, yet some may be genuine fans.