As I’m autistic and ADHD and I had little experience with a partner that might be also on the spectrum. And a lot more with an ADHD partner.
Try things often, start small, experiment. Try some shower/bath foreplay. Share fantasies. Start a separate chat/group/app just for the two of you, where you can share only spicy material.
On the bath topic perhaps the obvious is to remember about hygiene. Learn your anatomies (pull the foreskin if you have one). If possible get some intimate washes. You need only to get the dirty stuff off. Delicate antibacterial soap if you intend to eat ass (wash only the outside). Don’t have to go to very dedicated methods, like the popular company that names their products after gardening equipment. Test all new cosmetics at least a few hours before you want to do the dirty. You don’t want to discover an allergy at that point.
You may try flavoured lubricants or intimate perfume, but I haven’t used the latter, and the flavouring may be an allergen.
Edit: also there are flavoured condoms if this is the equipment you’re packing. Same precautions as above.
One unexpected advice is go vegetarian or vegan. This especially changes taste of sperm for the better, but also a better metabolism means less issues with other secretions (f.e. me staring a diet, before going vegan fixed my acne issues). (Also remember B12 supplementation, but this is better consulted with a doctor, if you have the availability.
Now if all that fails and you feel that something’s off you may want to see an dermatologist, urologist or a gynaecologist, depending on your factory equipment. (If you have modded the equipment to suit your needs then you probably already know the appropriate MD.) Medical problems can also have intimate consequences. F.e. circulatory or metabolic problems (diabetes for one) can cause erection problems.
Yes, it’s possible: https://buttplug.io/