Hmmm... while definitely NOT helpful, I don't think he was being RUDE .... ON PURPOSE. Sometimes people (i.e. guys) come across as rude because they really don't know how to convey what they're thinking in a positive and uplifting manner.
Now - if you said he was a jack*** on many other occasions and generally treated you with utter disrespect, THEN I'd say, yeah, he's a rude d-bag and needs to be kicked to the curb. But just going on what you've told us, I think he's just completely clueless about how to be supportive of your weight loss efforts. Bless his heart.