A little bit of advice

I think this could be an age thing as much as an ASC one, a lot of guys think they only have to say it all at the begining and that you'll know how they feel. Is he feeling less amorous because of normal age related male issues? I think a dropping off in intimacy is quite common in any long term relationships, but with people with ASC it can be more marked as, as a bunch, we're often not that comfortable with being touched and feel pressure to allow ourselves to be touched, which effects intimacy.

I'd try looking at the 5 Languages of Love and see which types you both are, the book itself is heavily Christianised couples counselling, thst part of it didn't do anything for me, but the actual languages did. They are about what you need to feel loved and appreciated, it might be that be of you needs words of appreciation and the other gives you gifts, the gifts are very nice but..... The gift giver is probably asking themselves why their gifts aren't valued as symbols of the love you share. It seems daft but people can be together for quite a long time and not know this about each other, but once identified and each party gives the other what they need, things get a lot easier. This might be a more playful way of getting into a conversation about your relationship than having "A Conversation" where he feels pressure to say what he feels, when he's quite possibly having some sort of brain fart. I think many ASC people find their minds go blank and they freeze when asked directly how they feel about something, then they feel bad about not being able to answer, which increases the pressure next time the subject comes up.

Try and think outside of your box too, if he asks you why it's not obvious how much he loves and cares for you, take that on board, don't make it an us and them thing, but really try and think why you need to be reassured a lot? It might be that his family/parents weren't demonstrative towards each other and your's were, we all internalise these early childhood behaviours we observe around us.

Thanks so much for your response. I feel so much better being able to gain more effective insight and being able to acknowledge that my lack of understanding needs addressing. They are great ways to look at the situations and yes I'll definitely give that a look.

There is a bit of an age gap between us me being the older in our relationship I'm 38 and he's only 27. This isn't an issue within our relationship we're both happy with this but obviously I appreciate it can impact our views and stuff. 

Also this is his longest relationship so I acknowledge now this is new territory for him to navigate which is why I wanted to increase my understanding to ensure we are able to work effectively as a couple and as a team together as we are soulmates as well as fiance's and want this future together we have planned.

Thanks so much for your response. I feel so much better being able to gain more effective insight and being able to acknowledge that my lack of understanding needs addressing. They are great ways to look at the situations and yes I'll definitely give that a look.

There is a bit of an age gap between us me being the older in our relationship I'm 38 and he's only 27. This isn't an issue within our relationship we're both happy with this but obviously I appreciate it can impact our views and stuff. 

Also this is his longest relationship so I acknowledge now this is new territory for him to navigate which is why I wanted to increase my understanding to ensure we are able to work effectively as a couple and as a team together as we are soulmates as well as fiance's and want this future together we have planned.