Give us some hints other than his sexual preference. You can't give him a boyfriend. And that's the only thing i can think of that depends on sexual preference.
What are his hobbies? How old is he? How much do you want to spend? What sort of things does he like? What's his style? Do you feel able to discern whether some item you see in a shop is his taste?
I mean, if he happens to be one of the guys who wear jewelry and make-up, you should not give him fishing equipment. If he is a tough outdoor person who loves to go camping and ice-hole fishing, then maybe a glittering T-Shirt is a little out of place.
Seriously, my friends never look at a present and go "ah yes, the bisexual will love that." Sexuality doesn't define a person. Look more into their interests and what they like other than other people. Or if they are newly come out or just want to express pride, Gay Pride sells a lot of merch like jewelry and such and some goes to LGBT charities.
I was wondering what I should get for my friend who's a cat, too! I mean, he's a TOTALLY different species so I really need help!
His sexuality doesn't define him lol, we need more than that.
You obviously see your Gay friend as not normal to ask the question....aint that homophobic or sumin?
hmmmm maybe a scarf, decorations for his house/room. love and pride accesories.
His sexuality shouldn't matter, get him something you think he will like.
Get him a Huge naked guy picture. ( ; always gets em
Oh please im sure thats not the case
Hmm, do they make gaynip?
It's called marijuana :P