ok so like is Zero straight because I heard if tu drink from another blood tu are saying tu amor them.

yes zero is straight. thats the reason y he craves yukis blood even tho kaname gave him some of his, is because zero likes her so u will only crave the blood of your love.

Well, drinking Yuuki's blood on its own doesn't mean that he's straight/heterosexual. vampiros will drink the blood of people they don't necessarily amor - for example if they're starving, o if they're fighting that person. But dado that Yuuki's the only person he's ever shown an interest in, we can assume that he is heterosexual.