Let's even say for a second that it is a choice. Does this somehow make it okay to treat homosexuals as lesser citizens? Of course not. To me it really doesn't matter because it's completely not my business who someone loves or has sex with.
In that vein, I vote to make incest legal, I think siblings of adult age should be able to marry. You have to agree with this, else you are saying they are lesser citizens and denying them rights.
Oh wait, is that gross to you? You can't use that as a defense to deny them their rights and treat them as lesser citizens.
See, I can use this defense for a lot of things, where does it stop? People marrying animals?
Yes, because animals are not people capable of engaging in a marriage contract. Really? is that the best you can do? But since you mentioned it, where's your protest against West Virginia's weird sex laws. It is legal for a male to have sex with an animal as long as it does not exceed 40 lbs. there. Insert random WVA joke here.