Am I Biual or bicurious?

Ok well I was watching last night and I came across some gay . I clicked on it out of curiousity and I got semi erect. Ive never felt this way before and have had ual relationships with girls and never thought about having ual relations with a guy. Is this me Discovering I'm bi or just because I was watching and I got over it? I would like answers from bi and straight people who may have gone through this. Nothing against gays but I'm 100% sure I'm not gay.