I believe the right should be there but I wouldn't say it is mandatory. People on the 'No' side have all given good points but they seem to talk about it as if children are trying to be forced to have those parents. If the child wants those parents and the parents are available, they most definitely should have the right. For example, an adopted daughter of gay parents wants her biological mother in her life. If the biological mother has agreed to be in her life, we shouldn't stop them saying "You don't have the right!"
The sex of the parents are irrelevant when raising children. There are no actual benefits of having two parents of the opposite sex. What matters the most when raising a child is the parent's actual parenting skills, mental, emotional and financial stability. Therefore children do not have a "right" to have opposite sex parents. Some children are fortunate enough to have any parents at all. There are plenty of gay parents, single parents and legal guardians who are much more capable of raising children than many so called "parents" of the opposite sex, and their children are raised in well-adjusted, financially stable environments and receive proper education.
How would this "right" be enforced? Probably unethically. Some parents just don't want to be in their children's life. Some parents are gay. Some children seek emancipation from their abusive parents.
Is having two parents of each sex the measure of a good childhood anyways? That doesn't seem very accurate.
I've been lucky enough to grow up with a motherly, loving mother and a fatherly, equally loving father. However, I know some fine healthy people my age who were raised by parents of the same sex. I know even more fatherly mothers and motherly fathers. What really seems to make the difference is whether the child has two parents at all. It really takes two people to juggle the needs of a family with kids, but assuming said kids don't come out too fast, those needs don't increase enough to need any more.
This question in fundamentally flawed by ignorance & I will state how in my statement. It is a flawed question because the only way a kid can have a parent of each sex would be a polygamist family which is even more so frowned upon than homosexual marriages. There are not only two genders; there are three. Male, female and intersex (yes all different biological genders). The only people to say yes are going to be anti-gay marriage people who lack the knowledge of there actually being more than two genders. Children should have a RIGHT to LOVING parents, not male-female parents. I'd rather have two dads or two moms that loved me, than a mom & a dad that didn't love me.
Children don't have the knowledge nor the legal ability to make such choices. It's not like they are adopting a teenager who can make such choices. These are babies and toddlers, who cannot know enough to choose anything outside of what the want to eat or drink. Though even that may not be right to choose if their dietary needs are specialized.
The Yes case would not be them choosing but some idiotic campaigner making the choice for them.