He's never gone for the fork but I'll keep an eye out if he does start doing itI thought when the tube sticks out it's a female. Also, be careful with putting the fork in the tank, my cichlids sometimes charge my spoon and slam into it as I'm about to pour food at the surface, so a fork could injure them.
Do you think you can get some closer up shots of the vent?
During breeding season, a males vent will show up, so that could be an indicator of it being male. It will be more of a pointy shape, while a female’s is more flat. The females will also have rounder fins than males, but you can’t really trust that method because there are some females with pointy fins as well. Are there any other blood parrots in there? if it were a male it could show breeding habits by chasing (during breeding season though). So it is kind of hard to sex a fix without it being breeding season.