Only sure way is to ask him but he may not tell you the truth.
Honestly
with words
When he starts liking girls too.
lesbians can say they like a guy non-sexually if they hav a sexual attraction for a guy then theyr bi
Okay well first is your guy friend bi aswell? If not dont go onto him. Youd just freak him out if anything.
He is bi-sexual
first, ask him what he thinks of girls that are bi. if he doesnt mind then let him know. if he does mind then just tell him you wont do anything with a guy or girl to loose his trust:)
if you just met him.. you might want to wait a lil and see if he likes boys or you are going to freak him out..
Then just be friends with him.
If you have a penis and you like other penises then your gay If you like them both you a lezbo theres no suck thing as bi
Go out with which ever person you like the most
uhh, you ask?