Boy troubles

So, my best friend and teammate has been liking a boy for 3 years now and the boy is also my brothers best friend. The boy and I have been talking for awhile, and I was thinking about asking him to homecoming but I do not want to hurt my best friend or I don't my brother to be mad....what should I do? I need a lot of advice....also this is the first boy I started getting feelings for after obsessing over a guy for 5 years.