you are insulting them saying they cant even understand plain english, you dont have to live in USA to understand what "interested in" mean in that context , there is nothing innocent sounding in that expresssion, and i'm not english nor have an english culture. Dont take aliens for fools.
I'll give you a relevant example:
Back in ~2006 it was possible to do similar searches within your college.
A disproportionately large number of people declaring their interest in both men and women were from China. Now it's possible that Chinese students were much more likely to be [openly] bisexual than British and European ones, but every shred of evidence I've ever seen (at college, in the media and living in a relatively-liberal ethnically Chinese country) points to the opposite.