I'm going to snitch on my friend to her mom because she mentioned to me in explicit detail that she sleeps around a lot
Do you like your friend?
No she's a worthless piece of chicken shit.
You can stop liking a friend, but you shouldn't betray them. Other friends will think you lack loyalty and distance themselves from you.
I don't want to be loyal to a slut.
It's ultimately your choice, but there really isn't a reason for your to purposely get them in trouble. Snitching on them will definitely cause drama and them retaliating is a possibility.