Girls, what type of tan line do you prefer in male?

I was planning to make swimming as my hobby. I will buy cycle shorts/swimming bikini tomorrow but I am undecided of how long should I choose the cut/length of the short.

Naturally, I have white complexion and definitely I would get tan line if I always swim. (I don't wear shirts while swimming BTW.) My height is 5'4 and body type is normal/slim.

Would you prefer tan line nearer to the knee or nearer to the crotch?

And also tan line above the waist or below the waist?
Thanks!