A)Anakin was nearly 10 years younger then Padme when they fell in love and everyone were OK with this
B)If you're sending 15 year old kids in a war where they're killing other people, then you must understand that they have right to choose with whom they must be (as a sexual partner).
Also this would change the course of history of SW, basically ruining Palpatines plans for Anakin.
Here good example of their possible future if he choose Ahsoka and goes with her.
https://www.fanfiction.net/s/11935788/1 ... Less-Taken