Birdo and King Bowser Koopa are from Nintendo's Mario and this screenshot's taken from Valve's Garry's Mod. It is a gift for  DevonTheFireWolf.

The Koopa king himself has a very crush on this very chunky and big-bellied female Birdo that he chose to impress her by eating lots of food back at his castle and return her to show off his recently bloated stomach. She is surprised and is like "...oh, my..." Looks like His Majesty's plan is working, so far.