Your sun/venus conjunction falls exactly on his North node, and this is a lovely aspect to have between you. It gives a lot of love to the relationship, and promises this will grow over time.
His Jupiter is opposite your conjunction, on his South Node, so this adds joy to the formula.
You have several close conjunctions of the slow moving planets, which are generational, so you will have similar energies in these areas.
However, your Neptune's are conjunct, and they oppose his sun, making him a little too dreamy, shy, overly sympathetic to the plight of others, and not overly realistic. which can be a disappointment for you.
Your sun on Venus indicates the type of male figure you are attracted to, so he would be "Venusian" in some way. Charming, good looking, sociable. Perhaps having strong libra or taurus in the chart, whether sun/moon or the angles.
He doesn't present these qualities, although he does have mars in taurus. Unfortunately, it squares your mars in Aquarius, so there is attraction, but it isn't an easy fit and the energy can turn into irritation and arguments.
His moon opposes his mars, creating a T-square with your mars. The moon/mars contact is also very physically drawing, but the sexual side can fade into conflict when your actions offend his feelings, and his emotional needs get on your nerves.
Your mars on his Neptune will tend to create misunderstandings, inaction, disappointment. Your energy seems to get no where sometimes, meeting up with a nebulous cloud, while his dreaminess gets shaken up by your down to earth mars energy.
The 4th point of the T-square, the point that gives an outlet of the T-square energy, is Leo, where he has his sun. So, his "Leo-ness", his fun side, generosity, will help save the situation by unfusing the drama.
His mercury is opposite your mars, so at the beginning you can excite his ideas, but after time you will anger him, while you will be irritated when you want to take action but he is mulling things over.
You two do have a Venus square pluto, which is sexually attractive but can become very possessive.
His Saturn trine your mercury was very helpful in helping you in your need, understanding and patient.
Now that we have a context from the synastry, we can look at the composite you posted, which shows how all these energies combine to express themselves in the relationship.
Notice mars at the top, forming a T-square with pluto and sun. That sun/pluto opposition will be power plays that develop between you. Pluto exactly on descendent is very powerful and strengthens this tendency.
Sun trine Neptune puts a spiritual, dreamy gloss over the identity of the relationship, and Jupiter completing a grand trine with them gives a sense of being lucky, of expansion and well being between you.
The moon opposite Venus shows the basic affection between you. However, notice they are somewhat separated from the rest of the chart and not well integrated, which weakens their energy.
This is a nice relationship to have as what is called "friends with benefits", or a fling, but valuable as a friendship.
