It's a fine dream, but you must consider that the defining characteristic of rape is lack of consent (ideally, clear presence of non-consent, but that's a big fish to fry). By all means cultivate an interspecies or age-transcending sexual relationship, but how will you ensure that both parties are on the same page consent-wise? Humans are quite bad at reading signals from other animals, and children are quite bad at making important decisions that can have lasting consequences.
It would be a good start to modify the cultural stigmas surrounding sex and rape. I admit that, having never been on the giving or receiving end of rape, I'm not an authority on the subject, but from what I can tell, rape victims are conditioned to think they've been permanently ruined as people, and outsiders seem to view rape as a capital crime worse than genocide. Being forcibly put through intercourse is harsh, yes, but hypothetically, if rape were viewed as a shameful but relatively minor offense, and the victims were treated with sympathy but reassured that it was nothing they couldn't get over (or need fear in advance), I suspect the actual experience would be less emotionally scarring for them. If it goes well, then we could broach the subject of allowing relationships with parties that can't give admissible legal consent, e.g. children and non-humans.
Tl;dr: I see your rambling and raise you my rambling xP