Hi,
That one would be Scene 7, if you have the walkthrough that one is in there, only the new v.0.14 is missing.
In order to unlock it you need to go back to Steph's house on Day 9 when she invites you to stay over, but do not have anal sex with her when she cannot find the condoms!
She'll give you a blowjob instead and it will unlock that scene.
Hope this helps!
WP