Well they use condoms. And the uke didn't seem to be in any pain which is a bit unrealistic. For the most part i thought it was pretty accurate.
Oops, they didn't use condoms
the uke was prepared by his partner properly.(it probably didnt show past one finger ,but a three finger width is the 'proper preparation width or size for most' adding in lube to the mix helps out a lot) also after a guy gets off normally they are emotionally, and physically more vulnerable to their partner so the uke was probably feeling a lot more pleasure than pain because of the body responding to his partners touch.(dont ask how i know this, i was innocent till i got curious and typed in questions on the search engine.)
Realistic first time sex? Maybe not, but a helluva better than most other stories out there.
And I like that a lot.