This reminds me of something that happened to me last week:
I was talking to this girl while walking to my car in the parking lot. She gets in the car as I wait for my bro to come so we can leave. When she gets in she says
Her: Do you think your good looking?
Me: Yeah
Her: Do you think I'm good looking?
Me: Yeah (but I said it in a way that she didn't know if I was serious or not. I basically acted like I didn't even know what the question was.
Me: Hey, do you think that your insecure?
Her: Uhh...sometimes.
Basically, say something like "are insecure because you don't know how I feel about you?"
or just acuse her of trying to get into YOUR pants
"Wait, wait.........I thought this was a nice conversation about _______ and now all of a sudden you want to know about my love life? Are you trying to seduce me?"
Depending on the situation you could follow with either:
"Because it's not working." OR "Because it's working."