This initial lack of interest should be expected given how our minds work.
For many partners especially those with ADHD, getting started can seem overwhelming. Until the neurons of interest are firing the ADHD mind is simply not engaged.
How many times have you had to convince your spouse to go do something? Only to experience that once both of you are out having fun, they tell you they are having “the time of their life and are glad you convinced them to go.
Guess what, initiating intimacy is really no different. Offer a little notice and a drop of persistence, and you might find that once your partner gets engaged in the dance of intimacy, they may soon discover that they too are “Having a really great time!”