Extremely expensive and exhausting process. Your romantic interest can also effect your ability to be a good parent. Not recommended.
Of course there is a low probability of adoption for sexual relationship, but if the media comes across one case it will demonise all of us and make it even harder for children in need to get the parent/s they deserve.
In a perfect world, pedophiles should be able to adopt. But then, if you have a sexual attraction to the child you adopted, even if you do not act on it, it can effect the adult role you should have. It is similar to the baby sitting question that I answered right now. It is not a healthy relationship in my view, that is all. Being authority to your love interest is not what I can call healthy.
That is only my view. I can seem conservative or anti progress but I would not vote against any laws that allowed it. I only have my objections and questions. Hope it is no offense.