Should i be feeling hurt?

Yesterday i had my fwb**we kinda do more than just sex together** over at our place to help us move some stuff. my sister was home and she recently had a baby like four months ago but she has regained her nice bodied figure. On the other hand I am more of average bodied but I am working on loosing some weight and he knows that. So we went out for movies and went to his place later. Right after the 1st round of fucking he goes "" you shouldn't get fat you see your sister and she just gave birth dammn"". That really hurt me like really bad i just asked him to drop me off at my house. I just woke up and I still have this feeling. Was I justified to feel hurt or I am overreacting?