Using Whole Sign Houses it's possible to do a little synsastry but it still needs to be treated with care because the other two classical planets, Jupiter and Saturn are not mentioned and, despite what some Modern Astrologers might think, they are 'personal' and indeed always have been treated as such.
So he has his Sun in your First house, though as you don't say whether there's any planets in your first we have to be careful. The Sun is your Ascendant ruler so there's a strong connection here - his mind and yours have a real connection.
Your Moon and his Moon are in a trine - that is they are in signs of the same element and the same gender - there's a connection again, and one that makes for easy understanding of each other's instinctive responses, Vettius Valens says that the Moon influences that part of us that wants to sharea life with someone - it influences our marriage decisions. There will be some differences. His Moon is ruled by Mercury and as Mercury is in Cancer, there's a mutual reception between the two. Saturn rules your Moon, but you don't give Saturn's placement so it's difficult to know if there will be some stress or some further strengthening of the link. As you were both born before Sunrise, you are both 'lunar' oriented.
Venus is connected to 'love and yearning' - love here is both romantic but also related to hobbies and activities and the way you dress - love of 'play' love of fashion, etc. Venus too is good for relationships. Your Venus is in your second house (using WSH) ruled by Mercury in your third. There's not a connection between the two by aspect. His Venus is also ruled by Mercury but his Mercury is in Cancer and so it is connected to Venus by aspect. His Venus is in the fourth, yours is in the second, not great connections for romance but as they are both in conjunction - his Venus and your Venus will tend to 'co-operate'.
Mars is, according to Valens 'in general a significator of one's masculinity'. Now Valens wrote nearly 2,000 years ago, so his statement might not be culturally PC any more but his Mars is in Gemini, his first house - it's ruled by his Mercury and that is in Cancer, Gemini is a masculine sign but Cancer is a feminine one, ruled by the archetypal female signficator, the Moon. He's a man but he's not one that feels he has to exert his masculinity all the time. He's more gentle. However his Mars is square to your Venus, that's a more stressful relationship. At a romantic level you might find some tension - though tension can be a useful in a romantic situation it has to be channeled and that requires effort. You will not that the same aspect applies to his own Mars/Venus relationship.
Your Mercury is in Libra, an Air sign and Mercury rules the Air Triplicity by night, so your Mercury has some dignity in your chart. Mercury is concerned with education, communication and intelligence - generally it signifies your rational mind. His Mercury is in Cancer, it squares your Mercury - I suspect that whilst you communicate and communicate well, he's more likely to blend his instincts with his rational thought processes. You're likely to be rather more oriented to reason as your Moon is ruled by your Mercury, the reverse of his position. That's not in any way going to block communication as the two Mercury's are linked by a square - but it's another area that you might find a little tension. I'm not going to stress that - his Moon/Mercury combination works well because of the mutual reception, so this could be something that you hardly notice and the Mercury/Moon combination is there for both of you. Communication may be a little easier than the square suggests.
OK that's a sketch. It cannot be taken as complete by any stress of the imagination - there are planets missing that could change things significantly. The degrees of the planets also will influence the final situation though more through intensity rather than anything else. Finally, I've used Whole Sign Houses - Most Western Astrologers would use a quadrant house system, such as the default charts generated on astro,com (though WSH houses are an option there) and that might well lead to one or more planets changing houses. The planet's rulers will remain the same though - that mutual reception between his Mercury and Moon will not be affected.