Sometimes the best approach is the most obvious;just be open with him. But will that be possible with your moon in Virgo and Mars in Aquarius? Both can be quite calculating and project cool indifference; keeping their feelings(moon) and motives(mars)bottled in intellectual analysis.
Your Mars in Aquarius squares his Asc(I assume), which explains the fixed sign attraction(Mars in a woman shows what kind of man she's attracted to).
This can also be a stumbling block because whilst Aquarius detaches from feelings, Scorpio swears by them. Perhaps you remind him too much of the tension between his own Asc and Mars sign? Perhaps he just doesn't want to come across as over-emotional.
But given the time that you two have known each other for a while now, I suppose its its the moon signs that are playing this game of cat and mouse.
Let me see if I can add my two cents worth;
With Cap Asc, its likely that his moon falls in your 11th house(friendships). He definately feels very close to you. But with ever-suspicious and tense Scorpio energy, he may be too unwilling to relax and just let it "flow".
Also the Square with Mars doesn't help matters. Aquarius always wants to maintain some "distance" between them and the one they care for: It prevents things from being complicated(as far as Mars is concerned).
Any other planets like Venus/Mercury will add emphasis to this bond on his side and create a feeling of losing control when being with you(Aquarius) but ironically, wanting to be in your company a lot more(Scorpio).
With a Scorp Asc, your moon falls in his 11th house. Yikes! A double whammy.
You probably feel just as bonded to him but Virgo often wants to tear apart and analyze whatever it is attracted to: Find what makes the other tick. This is how their able to "manage" the appropriate way of responding when relating to the person.
You also have Mars/Sun action in Aquarius/Scorp respectively; this can make decision-making on both the emotional/intellectual part quite difficult. No wonder the emphasis on the analytical moon. You are trying to strike a productive balance.
However, with moon signs in Virgo/Scorpio(both known for their tendency toward privacy) it may prove a little challenging. One of you has to give in and both of you are control freaks(in your own respective ways)
Your Sun falls in his First house. This adds to the feeling of familiarity between you two and a soul connection. You may gain a very clear picture of what your long-term goals are and be able to recall what gives you sense of vitality when with him.
His Sun falls in your 3rd house; he sees that being with you allows him to be a lot more versatile, to be more expressive and a lot more "in tune" with what is going on around him. Is there perhaps a square to his sun that is preventing this playful energy to emerge too?
The only obstacle could be the all too familiar Asc/Moon square Mars natally as well as in synastry that he has to contend with.
On your side, you'll have to deal with both yours and his Mars squaring your Sun. And your moon opposing his sign.
Hopefully this tense action between you(which can easily translate to an attraction), won't fizzle out to arguments, disagreements and fights(due to projecting to each other the square action shared nataly)