What is the source of this animated GIF of a couple slapping each other in play? Does anyone know the manga's name?



Thanks in advance n_n
Note: This is a bit too long for a comment, but I'm not really sure about my answer. If something is egregiously wrong, I'll delete this.

I ran some reverse image searches and noticed that the GIF appeared to be created from this image set:



The Tumblr source links to a now-deleted Pixiv entry by the user ましき　＋　まこる. Given the lack of series-specific tags on both the first Tumblr source I found and this one -- they simply state "Pixiv" and some generic description tags -- I'm inclined to suspect that this might be original work (or at least some sort of doujinshi). However, I can't read the Japanese of the caption of the second source, and so I may be missing something from there. Moreover, since the original Pixiv image appears to have been removed, it's hard to say.