So many ignorant people don't realize that in most countries, incest applies only to direct siblings, parents, or children. In some places it's okay to fall in love with your cousin. Also, the whole genetic defects issue is a bit more serious when you and your partner share DNA from the same parent. A cousin is your parent's sibling's child so you share no parental DNA. Lastly, defects in incest is only a problem if your family has records of it in your ancestry. You're more likely to have a baby with defects marrying a random person than wit your sibling in most cases.