My friend bleeds when her boyfriend fingers her

Shalom
So one of my best friends is dating and when ever her boyfriend fingers her she bleeds. It's not like a lot of blood or anything, but it's enough to cause her to worry. We googled it and it said it may be a tear in the uterine lining, but there's no pain and it's literally only when he fingers her. Any possible explanations or help of any kind would be greatly appreciated! 😊