For one thing, don’t think the opposite of “contempt” is “respect”, I think it’s “admiration”. My husband thinks I am one of the coolest people in the world. If I cured cancer, he wouldn’t be any more proud of me, because he already assumes I could, if I wanted to. He thinks I am clever, funny, and cute. He thinks that out of all the women in all the world, he got the best of the bunch, and I feel the same towards him. He’s just awesome.
Contempt is when someone thinks the person they are with is inferior to them in some fundamental way: not really as smart, not really as capable, not really as attractive, not really as talented. It’s when they think the other person is the one that got lucky in the marriage, when they feel like they “settled” just a bit, or made a choice that is beneath them and now they are stuck.
So I wouldn’t work on respecting your wife, I’d work on admiring her. If you don’t admire her, I hope you did at some point–try to get back to that place.
As far as teasing goes, I think it’s all about ratio: it’s ok to say wise-ass, teasing things if they aren’t all you ever say. There need to be non-ironic words and deeds that show that admiration. It’s the only way for the other person to be sure that jokes and teasing aren’t a passive-aggressive way to be insulting.
Also, you can’t tease her about things that could possibly be true. My husband will tease me about being crazy and stupid. This is funny because I have no insecurities about being crazy or stupid, nor would I think for even a second that he thought I was crazy or stupid. If he’d ever, ever, ever given me any real reason to doubt his sincere admiration of my intelligence and good sense, those jokes wouldn’t be funny anymore. When I was overweight, he never, ever teased me about my appearance because I really was uncomfortable about it. Now that I feel pretty good about my weight, he’ll tease me.
Teasing in front of others is also a big deal. I’m not saying it can’t ever be done, but the rules are different. Public humiliation is a hard emotion to deal with, and hard to forgive someone for causing it. If you know you have trouble recognizing where the line is, I’d make a resolution to just never, ever, ever say anything negative about her in front of anyone else.