The stories have broken from a podcast from Tortoise Media called 'Master, the allegations against Neil Gaiman'. I have not listened to any of it, but have read these two articles from Tortoise, which provide summaries of events and his responses:
In three of the cases, he claims their relations were all consensual. In two of them, there are NDAs, and one of them is described in some detail in the second article.
In the last one, he claims he misread a situation and stopped as soon as he realized it.
It's not looking good for him, that is for sure. I think he's hoping he can deny everything and it will blow over after some time, but it keeps getting worse. It doesn't seem like anything will result in criminal charges, but there is a lot of smoke around him.
I'm still a fan of his work; it's been a huge influence on my life, so it's causing a lot of difficult feelings.
The absolute, almost guaranteed didn't happen best case is that everything was consensual and Gaiman is just the kind of 60 year old who goes after 20 year old women which is... still not a good look, and I'm also having conflicted feelings