Talk:Happy Quinn-Curtis/@comment-94.119.96.1-20170728193523/@comment-24659868-20180118145600

Sometime between 2x13 (when they begin dating, albeit secretly) and 2x17 (when we learn that they have definitely slept together).

EDIT:

Haha, just realised what you're asking (should have read your question properly! xD). The episode we find out they hooked up is 2x17. :)