Just as an aside - if your child came out as being gay and hence they are unable to get married (as the law currently stands), how would you approach sex with them from that perspective and would it make a difference if you had a son or daughter making this decision?
For me, it wouldn't change anything - but then I'm not religious or hold any kind of prejudices about gay/lesbian/bisexual sexuality. Plus I think that law is rather disgusting and discriminatory, but that's a whole other debate. I would like to think that I will be able to have the kind of relationship with my kids that they could come to me and talk to me about their feelings and know that they'll be accepted the way they are.