If your husband is doing anything to send mating signals (i.g., petting beak for some macaws or places other than the head or neck, I would strongly urge him to stop, as it often sends the wrong intentions and intensifies mating behavior which includes him attacking both of you--- you first, as you were the threat and then your husband, because he may have sexually frustrated the parrot-- not blaming him, but it is super easy to do even with a parrot who doesn't have a complicated past). The same should be said about any huts, blankets, hampers, boxes, shadowy spaces etc. 10-12 hours of sleep on a schedule (quiet and dark, like a toddler) is also essential, as parrots regulate their breeding cycles via light and their mood and immune systems go downhill without proper sleep and light/dark cycles.
Just saw your post above after writing this first part. You need to all be clear that not a single one of the family is his mate. No cuddles...no shadows....plenty of sleep...lots of time out of the cage...teaching him to play...do not force him to do anything he is uncomfortable with (within reason). You need to all build trust but set firm boundaries in terms of this being a non-sexual relation. It's going to take a lot of patience and consistency and controlling the hormones is going to fall largely on you guys (while nature will still amp them up in the spring, that doesn't mean that it's okay to touch him, swaddle him, allow him under hair/clothing/furniture afterwards-- he should no have access to those spaces). This is even more important because of his complicated history. You don't have to walk on eggshells or make a super rigid routine, but predictability creates a little less anxiety (assuming there is a bit of natural deviation just to prevent overly-rigid behavior),
Also- avoid shreddable paper-type toys and warm mushy food during hormonal spells--- with these, there is some wiggle room during non-hormonal times, but with a bird like you are describing, that wiggle room should never apply to sleep schedules, petting inappropriately or shadowy spaces...Those things will need to be pretty solid indefinitely if you want this to stop and stay gone. His past is complicated and he needs constancy.
Find out what motivates him (other than sexual petting and "cuddles" and find ways to give him attention/praise in a new and fun way that revolves less around touching and more around a game, dancing, a puzzle, foraging, etc etc. I am not saying you shouldn't handle him, but do not push it if you know you will get bitten or if the bird is unsure, as that often leads to practice biting and the discovery that biting can be used to manipulate (I'm sure he knows this by now). Look into ABA as well (applied behavior analysis). It works when everyone is on-board.