Speaking from the perspective of someone had this happen, YTA (lightly though, ur not a monster). I get that your daughter and you clearly are more open about sex, but I remember when my mom casually left her stuff in the family restroom, as if it were no big deal. It crossed a line for me, and even though I never told her, it did change how I felt about her since she left it in there all morning and clearly knew I had seen it. I’m not even religious, but it was a big deal! You should have stayed on the side of caution with her boundaries with your daughter. Yes, sex is normal, but it is also highly personal and not everyone wants to know about your sex life (especially your kids)