No, not the sex, more like the lapses.
They both know that he won't let Iruka live even if he does tell, and the only reason Iruka doesn't give in to the perverse desire to spill and get it over with is because he is shinobi - and shinobi don't break until they're broken. Friends and honor and trust are all fanciful dreams, and Iruka knows this. The truth lodges bitter-tasting in his throat. But: DON'T BREAK UNTIL I SAY YOU CAN, his jounin instructor barks, and Iruka is thirteen and bleeding all over and exhausted. YOU DON'T BREAK WITHOUT PERMISSION, GOT IT? So he doesn't break. So he doesn't break.
It's a little... choppy, a little quick.
I hope this review will make more sense when I'm sober.