So what, to you, is the difference between bi-curious and bi-sexual? "Interessiert" sounds a lot like the word for "interest", which in this context (in English) is used more similarly to "attraction" than "curiosity".
- "I am interested in gay sex/you."
This gives the impression of actively desiring.
- "I am curious about gay sex/you."
This is more along the lines of 'if I even get the chance I may or may not take it'.
It's not much, but there seems to be some difference in nuance with interest/interessiert, which brings me right back to the initial question.
And these nuances seem to be the kicker here. In German "Curiousity" would be Interesse/Neugier, that is an active interest/attraction/observation to the topic at hand.
"Bi-curious" in this context would be a man/woman actively testing out several times if he/she likes it or a bisexual person open to "experimentation" with the gender he/she prefers less in bed.(Since a majority of bisexual persons prefer one gender in bed a bit more, 50/50 bisexual persons with no discernible preference are rare)
What happened to Hana, who slid into her bi-encounter totally unintended and never felt the desire to further pursue it, that would be in German a pure dabbler/"Amateur" or an experiment. A straight man/woman whose bi-fantasies are awoken by the (pleasurable) act or exploring existing fantasies. It could also be a hint that a person is bisexual, but he/she does not know it until this initial encounter and further experimentation.
Hana is experimenting/dabbling rather passively with few pursuit of her own with bi-sexuality, in German we would term it like that, "ein Experiment", "eine Erfahrung", "ein Zufallsversuch".
In English bi-curious might be the correct term for it, but not in German, where the translation of curiousity inherently always has an (if variable intensity) active pursuit of the topic in question.