My husband's co workers have been making fun of him...

For having a fat wife ! 
I am mortified. I found out because they have a group chat system and it was going off like crazy so I decided to check it. I usually get along well with his co workers and thought I'd be goofy and reply. 
I saw that they were saying stuff like "how's that walrus of yours? Oops sorry I meant wife*" And "is it really true that it's better to have more cushion for the pushin" 
I'm so hurt! I have gained weight...I'm 5'4 and 188 pounds. I'm also 15 weeks pregnant with our third child and had struggled losing weight after having our second child 17 months ago due to PCOS. I realize I'm overweight but do they need to be so cruel? :( 
I guess I just want and need some support