How can I make my girlfriend stop putting her finger in my anus?

Being stimulated in the anus during sex can be experienced as very pleasurable for some, because the area is full of sensitive nerve endings and is an erogenous zone that can lead to stronger pleasure and orgasms for some people. In addition, the prostate, which is often referred to as the male G-spot, can be stimulated through the rectum in men. Prostate stimulation can provide a very intense and different type of arousal and/or orgasm.

Some find it stimulating and extra exciting to insert their finger into their partner`s anus, but it is very important to communicate about this topic, as one should never cross potential boundaries without consent. As far as I know, this is not a spesific or widespread "cultural thing" in Norway, but rather a matter of individual sexual preferences, curiosity, and intimacy between partners. 

Regardless of your girlfriend`s reasons for doing this, it is crusial that you start communicating better. This will prevent it from becoming an even bigger issue or causing you to feel anxious and reluctant about having sex. To help with this, I have enclosed two articles: one on general communication and another specifically about communication and sex. I hope you find this helpful, and I hope you can continue to explore and be playful in bed together, so you can discover what satisfies you both sexually. Perhaps you might even come to enjoy anal stimulation, provided you are prepared so that the muscles can relax - and additionally, using lubrication is essential.

Best of luck!