Showrunner Ryan Condal explains the kiss between Aemond and his mother Alicent in #HouseOfTheDragon:
“He's somebody that was traumatized at an early age by his brother by taking him to a brothel long before his brain could probably process what was happening. As these things do, that trauma then manifests a certain way in his behavior as an adult. While I don't think that Aemond is necessarily in love with his mother, I don't think he's able to separate the feelings that he has for her from these other male feelings that he experiences.”
(https://t.co/oJMf8bDmVS)