Regardless of whether he was being more truthful or was only under the influence, he was broken and trying to make himself feel better by degrading Sara. He was influenced by emotions.

it's neither, it just lowers inhibition. so when you have that random thought like "what if i slapped that guy" you're just not going to stop yourself. that doesn't make you a good or bad person, everyone has different things going on in their head. what matters is the thoughts and actions we listen to and let live. like, no one is right all the time, but alcohol will make you feel like you are. leads to mistakes.

in this case I think it's obvious that Rudy didn't really feel that way, if anything he's just confused and rejecting the "maybe you just need to go it the long and hard way" speech that he just got. that was him grasping at straws "no, it's not because I'm emotionally damaged and need to work on that, she's just got too small titties!" which if he wasn't drunk, i think he's now mature enough to think about and realize obviously isn't the answer either. even if he was that shallow, all his other interests have had small breasts. like, it's so completely untrue that he couldn't be doing anything other than drunkenly trying to drown out the sad thought without thinking.

I do think he was being sarcastic, I mean, technically he's a half decent person. Just some strange coping mechanism manifested by a 'looser'