Me: Inexperienced, she's one of my very few sexual partners
Her: She's had 10x more sexual partners than me, likely around 20

When we met, she was in to sex a lot. We knew each other for about 3 weeks, the night we started dating, we had sex. Some days, we've had sex up to 7 times a day, when she's on like this horny "spree". This would put us at around 15 times a week during some weeks.

Now we are 6 months into the relationship, we might have sex once or twice a week, sometimes none. Given she is one of my first relationships, I never really experienced this. 

It's not that I don't initiate it, she's just like "okay, good night" as soon as I get in bed, like to the point where I don't even bother going to bed at 9 PM to watch TV some nights anymore, and I just stay up doing work.

This might be normal in some relationships I would think, but given she has a sexual past of enjoying sex with a number of people, I kind of thought she would still be into it still.

Is such a massive drop off normal after 6 months? Friends said it would die off, but I feel like what they say after being married for 20 years.
user
6 months into a relationship, sex life is 10% what it used to be. Is this normal at this stage?
assistant
Me: Inexperienced, she's one of my very few sexual partners
Her: She's had 10x more sexual partners than me, likely around 20

When we met, she was in to sex a lot. We knew each other for about 3 weeks, the night we started dating, we had sex. Some days, we've had sex up to 7 times a day, when she's on like this horny "spree". This would put us at around 15 times a week during some weeks.

Now we are 6 months into the relationship, we might have sex once or twice a week, sometimes none. Given she is one of my first relationships, I never really experienced this. 

It's not that I don't initiate it, she's just like "okay, good night" as soon as I get in bed, like to the point where I don't even bother going to bed at 9 PM to watch TV some nights anymore, and I just stay up doing work.

This might be normal in some relationships I would think, but given she has a sexual past of enjoying sex with a number of people, I kind of thought she would still be into it still.

Is such a massive drop off normal after 6 months? Friends said it would die off, but I feel like what they say after being married for 20 years.
user
sex life of my very first sexual partner starting to dry up suddenly despite having sex around 15 times a week before, not sure if normal
assistant