Imagine SoraYori, but instead of going to antarctica, these brave young men started a quest to go to Amsterdam and liberate from their deathly diseases.
Pulling out, Coitus interruptus, even when performed perfectly is not 100% effective, you are still gambling with the possibility of an unwanted pregnancy then on top of that it really kills the fun having to focus on pulling out at the right moment. It's "ok" for an spontaneous session with a partner when both agree at possible risk of pregnancy. Better get the condoms, pill or best of all a vasectomy.
Granny looking like she gonna harakiri after sex, better not fuck her to be honest.
Inb4 homosex doesnt count because they gonna explain it soon.
Also
>science explanation