The more I think of it the more age restricted sex laws seem absurd to me. It just seems like trapping the younger person away from having a close relationship from someone their elder. Personally, I would like to see more concern on peers than on an age disparity.

The only problem I have with incest is that that word means different things to different people. Okay, maybe more than that. The word incest is associated with inbreeding and abuse, but those are all actually separate things...so I don't like that word for that reason also.

Now if a sexually mature pair of guy and gal have enough consanguinity between them then I can see having a law enforced restriction because of the real harm that would come from them having inbred offspring. But that's inbreeding, not incest specifically. And that has a fuzzy boundary for what is "too close", roughly I would say my opinion is one's siblings, parents, aunt/uncles, and grandparents are too closely related and most of those have authority over you (getting ahead of myself here).

The main reason I would be against, say, parents and their children having sexual relations with each other is because of an imbalance of authority, typically parents and their children are not equals which I think is needs to be a prerequisite for sex. Allowing parent/child sex seems like a high risk scenario for the child to be abused by their parents. Or anyone related by blood or marriage who has authority over another person in their family.