The reality star poked fun of his girlfriend's attempts to shed her excess pounds after giving birth to their second child Penelope last summer and even made her cry, but Scott is unapologetic.
He posted on Twitter: ''Never realized how upset people get when a person makes a comment about weight.
''P.s anyone who has to much to say probably had to much to eat. #fatasses (sic).''
The 33-year-old beauty - who also has a three-year-old son Mason with Scott - has been open about wanting to exercise gently and eat healthily this time around, but Scott has been unsympathetic to her plight.
She famously collapsed while she was trying to shed her baby weight the first time around because she was so obsessed with slimming.
However, Scott has been openly mocking his long-term girlfriend about her curvier figure and complaining about her looks.
He teased: ''If I would have fell in love with you a couple of pounds overweight, this would be my ideal weight, but I fell in love with you when you were super skinny.''
Scott was then shown ranting to camera in the latest episode of 'Kourtney And Kim Take Miami': ''Right now seems to be probably the heaviest she's ever been not pregnant.
''When we had Mason I remember her trying to whip herself back into shape pretty quick. This time around it seems like it's the least of her concerns, and the only thing she thinks about are the kids.
''I just think that she would feel better if she got back into the shape that she feels the most comfortable in.''