Sex, our relationship, being honest and accepting.

I have recently found out that my autistic partner has paid to watch sexual activity online. Our current sex life is none existent and he's clearly told me that he's not interested in sex anymore. Now I understand this as sex is a MASSIVE sensory thing for him, a big overload, hence his decision. And I'm not upset that I have found this (phone bill) as everyone needs their needs meeting. And him doing that is meaning he is control and an overload will not happen as he noes his limits. However do I tell him it's ok and I know?

How would you respond if it was you? Would you be relieved I knew? Or embarrassed? 

He struggles with conversation about our relationship and any issues etc but he is afraid of what will be said. I know he loves me dearly and shows me in his own way that this is the case. 

Thanks for getting this far, appreciate it. x