AdviceWife called exs name out in bed!

So my wife and I have been married for 5 years now. Recently her ex boyfriend which they had a very messed up relationship full of drugs, abuse, addiction. She recently round out that her ex passed away. She was upset about this which is understandable to say the least. Yes they had a messed up relationship but they still loved one and other at a time. My issue is not that she was upset at his passing but about two weeks after his passing while making love and making her feel very good she called me her exs name. I slowly just looked at her pulled out and walked away and she was devastated that she did this and says she has no clue where it came from. I’m not mad, more confused. Was it a slip of the tongue because of recent events? Did I do something that reminded her of him during? Or was she legit thinking/wishing/dreaming of him while with me? Any advice would be great.