Hey IDK, first, good for you for having your own standards. You should NEVER feel that just because you're the 'only one' showing that you're offended or bothered by something that you're wrong. I just wanted to post a counterpoint. I have to respectfully disagree with the first page of posts saying to let it roll of your shoulders or just grow a thicker skin.
No.
You can definitely still value your own standards and values and reactions to things while still seeing it in a larger context and understanding where the teacher is coming from. They aren't mutually exclusive. I don't think you're saying the teacher is a bad person or 'sucks' just because he said what he did. You are allowed your own opinion and it is totally valid.
In this case, you have a direct relationship with this man (teacher) and he is in a position of authority over you and your peers. It's definitely within your right to assess whether you think he's acting professionally to your standards. Your reactions as his student are very relevant because it's his job to set an example for you in addition to leading a course for you.
Some people are more hierarchal than others, some not. I'm not a J, but I expect people in positions of authority to more or less act like it.
Anyhow, that comment about his fat ass girlfriend, I would've found very offensive. As a guy, he shouldn't be calling any woman a fat ass, even (especially?) his girlfriend. And especially in a room full of other guys signalling it's "okay" to talk like that to the girls in the class? And that girls shuold think it's funny and a term of endearment to be called that? Oh hell no.
I once had a PE teacher teaching sex ed who compared the hymen to a bag of chips. "If the seal is broken, you know it ain't fresh". Totally fucking inappropriate. Disgusting. Misogynistic. Blah blah blah. I wasn't in the class but a friend told me. He also had a reputation for feeling up girls on the soccer team (which he coached) Saying stupid shit can be a herald of doing stupid shit. We had a LOT of meat head unqualified teachers running around, because it was an international school that kinda scraped the bottom out of desperation for English speaking teachers. As an adult, I've seen a lot of dumbass young adults who can barely take care of fall into teaching 'just because'. So I have VERY LITTLE PATIENCE when it comes to 'bad behavior' in teachers.
Anyhow -- yeah, I can see why you'd be offended.
I think teachers and parents and adults these days feel a need to 'be one of the kids' and be friends with kids and have kids think they're "cool" or whatever the kids are saying these days. LAME. I'm too old school for that, I enjoyed my high school teachers who I could relate to and I would exchange CDs with them and shoot the breeze with but at the end of the day they need to act their age and their role. It's just like working with people -- I know my coworkers are people but at work, they have to be professional and get the job done.
Enough of that tangent, but IDK, yeah, I think you know you were offended and are looking for reassurance. Advice in general -- don't let anyone tell you you're wrong for that or have no 'right' to feel the way that you do. If you want to take your teacher aside later and explain to him how you feel, you can do that.