There are 3 important planetary points that define a person in everyday life; the sun, moon and the ascendant. Since we don’t know his birth time we don't know his moon and ascendant. His moon could either be Aries or Pisces, they are very different moons. Without these placements, his natal and your synastry or composite charts would be incomplete and inaccurate.
Im rusty, but quick look. You both have a Stellium.
His sun, Venus and mercury are in Cancer, but we don’t know what house these are in. This can be very vulnerable for a man because of the increased sensitivity of all those planets in Cancer. It would be hard for him with all this emotional energy. He would have to trust completely before allowing himself to open up.
Your sun, Venus, mercury, Pluto and AC are in Scorpio in the 12th house. In Scorpio, you are controlled and deliberate in your decisions, mysterious but hidden in the 12th. 12th house has always been hard for me to understand and describe.
Your suns are trine, but the aspect is wide. Neither of your suns are aspected by the other’s planets. This is important in a relationship as neither of you are seeing or acknowledging the others’ core essence as individuals.
Your moon is in cancer, but is not aspected by any of his planets. Are you sure you’re in love with him and not just infatuated? We’re not sure where his moon is and we don’t know what his ascendant is.
You have mutual Venus/mercury trines. You do enjoy each other’s company and have a mutual interest in the arts, music, culture.
His venus/mercury trines your AC. There is a mutual attraction here.
His Mars in Leo squares your Scorpio Venus. Double whammy. Mutual sexual attraction.
Btw, your 28.32 deg sun is conjunct my 28.1 deg AC in Scorpio, only 31 minutes apart. No wonder I understand and can relate to you so well.
Sorry, have been crazy busy. Hope you are well.