Chiron is an asteroid (well technically it's disputed what Chiron actually is, but for astrology's sake is classified as an asteroid), and is linked to our wounds. Chiron represents our greatest wounds in life, the ones that leave the biggest, most lasting scars, and also shows how we can heal and grow from those experiences and move forward more complete people. In love, Chiron can bring this energy to relationships, and can show a relationship that has the potential to help us heal, or to hurt us more.
Chiron Aspects & Love
Under positive Chiron aspects (sextiles and trines) to the natal or progressed 5th or 7th house cusps or rulers, or natal or progressed Venus, Chiron can help you enter into relationships that allow you to gain more insight into yourself, into your wounds and old baggage, and find ways of healing. This can make you feel better as an individual, and more secure in the relationship.
Transit Chiron in the 5th house can offer opportunities to heal issues that have impacted your ability to express love and affection, opening your heart up more; transit Chiron in the 7th house can offer opportunities to heal issues that have impacted your ability to commit, compromise, and be an equal partner, and transit Chiron in the 8th house can occur opportunities to heal issues that have impacted your ability to connect with others intimately, both physically and emotionally.
Hard transit Chiron aspects (conjunctions, squares, and oppositions) can make it easier to be wounded, and you may attract people to you on purpose subconsciously that will open up old wounds and make them worse. In a way, this can prompt you to finally heal from something that you've been avoiding as it makes it more obvious. But it can be a challenging experience. It's an experience that has the potential to wound you much deeper, to create even more problems for you, so you really have to lean into the healing and embrace it. Face the issues that you've been avoiding and don't look away when something comes before you. Take your time in relationships so you can build appropriate boundaries and not let in the snakes. Otherwise they may come for you!
Chiron & Synastry
When you have a Chiron connection with someone in synastry, this can show that this person has the potential to help you heal or hurt you badly. The connection can be strong on a spiritual and psychic level, so you may have a hard time resisting either way. But it's important to try and focus on the healing potential so you can avoid the hurting potential. Which is ends up being usually depends on where both of you are in your lives when you come together. If you're more secure in who you are and are open to growing and evolving, it can be a wonderful pairing. But if you're running from your problems, not ready for tackling those wounds, and insecure, then it can be damaging.
To counter the challenges of Chiron, some positive Jupiter in transit and synastry can help a lot! This can help you to be more positive and open in transit, and in synastry, you can like each other a lot which can help you manage any discomfort that may come with a Chiron connection in synastry. Moon connections in synastry can also help with Chiron since this helps you with comfort even more, and you can have emotional understanding so you're (hopefully) less likely to emotionally wound one another. Without emotional understanding from the Moon or the like from Jupiter, you may want to handle this connection with kid gloves!
Suggested Reading: Articles in the love astrology series on Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, the 12th house, eclipses, retrogrades, the Lunar Nodes, and the Asteroids of Your Name