The real talk about the growth process starts on Page 92. Throughout the comic I was blatantly hinting that Jake was going to have some very serious hormone rushes, and this one was the worst so far.
And yet, Jake was never briefed on these side effects. Which explains why he didn't take any precautions to avoid what he did in the first place.
Fun fact: While he did have children, that was the only time Jake ever had sex. While un-fox-like, Jake is in fact celibate by choice because he found the act really distracting from his non-war work.
That and he wouldn't ever do humans.