Is it good news for me that my husband did this?

why should it matter if he's attracted to her,the point is he cheated you and its never good.the way you say it its like it doesnt bother you that your husband cheated you but rather you just interested in knowing if he's not attracted to her yet you said they ended up having sex,of course he's attracted to her.to me thats disturbing,and may be you need to re-phrase your question!