I'm attracted to the wife of a family member.
Why do you think that you are so attracted to her?
She's a sweet little fox.
I understand that you can't control who you are attracted to, but you definitely should not act on it. You are supposed to be considerate and respectful towards family members. So, make sure you don't try to make a pass at your family member's wife.
Dude, I'm just 16, I can't date her, even if I wanted.
It sounds like you are have a passing crush and are only infatuated because of your inexperience with love. You'll get over her quickly and in time, find someone more appropriate to your age to fall in love with.