Been fucking my younger sister for a few weeks now

My younger sister came looking for work in the city so she asked to crash at my place while job hunting, I'm 30m and she's 22f, When she got a job, we celebrated by going out , had a few drinks, when we got home, things got escaled after we hugged each other and we ended up fkin, next morning when we woke and the drinks wore down, we avoided eye contact, She was making breakfast in her shorts and was bending over the kitchen counter to grab something, I got so hard and I grabbed her from behind, she kissed me aggressively and we ended up fking again, we both smiled at each other, We have done everything in the apartment in the last few weeks, love to stick my sweaty cock in her tight mouth after I return from the shift, she even let me do anal after a few drinks, it was the best feeling ever, and I love pounding her pussy but I always cum outside to avoid any pregnancy, It's going well, we both live together and go to work, We both r free to use and look at it as a physical sex, no emotions invoked, we just love to fuck, it's been going on for a few weeks and it's really really awesome, I hope this goes on for a while, any suggestions are appreciated