My general assessment is that unless an author who has good queer rep goes 'but X is straight', I tend to assume any character could be bisexual. (Or it's one of my characters.)

For OCs:

Ilphyl is pansexual and genderqueer (and somewhere fluid). They really don't do binary gender.

Bel is gay. No interest in women beyond aesthetic -- he can identify an attractive woman, but no interest in pursuing that.

Most of my other tabletop characters are in the 'has not come up'. That and I have Shakudo who doesn't really get gender or sexuality, because he's a goron, and one of my Saturday-tabletop characters is a robot (Artemis) who is also in the ??? category.

For canon characters:

Penric is a heterosexual cis-man sharing his body with a pansexual feminine spirit (Desdemona). He's also very monogamous and married.

Simon is bisexual, as are most fae in his canon, but again, in the 'happily married, no interest in adding partners at this time'. He does have a husband and a wife.

I'm trying out Aerich, who I tend to see as both demisexual and generally not attracted to people outside his species, which makes it hard to do romance/sex stuff.

(Also, I am playing a lot of male or AMAB nonbinary characters here; I should get more female characters.)