@maxdancona,
There are benefits to not hiding normal parts of your life from your kids.
My daughter gets to see how I act in a relationship. She is starting the process of having relationships herself (she is now a teen), and the more she can see adults having normal respectful relationships, the better. I talk to her about what a healthy relationship is, I want her relationships to be equal, and respectful and based on good communication.
When I am with my girlfriend my daughter gets to see this in action. The way I treat my girlfriend is the way I want my daughter to be treated and the way I want her to treat her partners.
On a somewhat tangential note, a couple of years ago my daughter was looking for something and found a box of condoms. She thought that was hilarious... "dad! you have sex!". I was a little annoyed with her that she had gone through my stuff, but I was kind of glad that she found them.
If I am going to teach my daughter to have safe sex, what better way is there for her to learn then by example?