I think the other scene you were talking about is at 2:00 on the link below. Most of the time if you know the episode or film you'll be able to find it online somewhere.
www.dailymotion.com/video/x3eew43
Dakota Johnson looks like she was tickled on the back of the knees or leg area by Leslie Mann. The link is below (remove the space):
http://123movies.to /film/how-to-be-single-11954/watching.html (@ 15:30)