If you can't tell the person that he/she is being condescending and disrespectful straight out, and you must tolerate it to a degree, i.e. you can't dismiss yourself from the person's presence, then I have found that there are a few things you can do to discourage such attitudes.
For one, there's direct eye contact. Every time the person is condescending, raise your chin, face them in a sharp motion, give the person a direct stare for several seconds. In other words, "I heard you...I caught that...." You can even smile if you'd like. This is a subtle way to discourage a certain behavior. When you are treated a certain way, I would be sure not to "wince" as you say.....stand your ground in whatever way you can. Don't allow the person to gain ground over you.
Depending on the personality of the person, there is also laughter....if their condescension is subtle, then a grin or a light chuckle, as if he/she made a joke. If it's sharp and abrasive, then a lifting of the eyebrows and a big cheesy grin or a laugh. In other words, you are giving them the signal that you aren't taking them seriously, in spite of how seriously they are obviously taking themselves.
If neither of those approaches is appropriate to your situation- in other words, you have to cowtow a bit- then I suppose I would just have to detach myself. "Yes Sir" and keeping things at a business level and impersonal. Let the person talk, but keeping my own responses short and concise and in the tone that let's someone know that we are not in a personal interaction. This removes some of the power from the person and makes you a bit "untouchable". It's somewhat like indifference. And again, it's a little about "I don't take you seriously, and your manner means that you have an issue."
A lot depends on context and how this person is related to you. Whether it's a boss, colleague, whatever. I myself generally prefer the straightforward approach, but I am not tolerant of condescension...doesn't much matter who the person is.
I suppose that this sort of interaction can become almost like a game....where you can approach the lunch with "I wonder what so-and-so is going to bring to the table today". And then almost feeling like a spectator to the person's attempts to put you in your place. I am no a huge fan of detachment, but when someone is making a concentrated effort to continually demean you, it is a powerful thing for you to protect yourself and maintain your ground.
Sounds like someone who really wants attention. lol
I would remind you that life is too short to allow your voice to not be heard and add elements of stress to it, like feeling like you have to participate in activities with people you find displeasing, but you're not looking for a solution. Just play a song like Chuck Berry's "My Ding-a-Ling" (or any song that instantly breaks the stress of the moment) over and over in your head as you're "interacting" with them. The mind is a powerful thing but direct your negativity in that situation towards positivity to make it more pleasant for you since no one else will.
Best of luck to ya! Remember, we've all been there to some point :)
Don't answer, just look at them. If they want to know why you don't answer then you have to have a boundry for yourself that you won't allow people to speak to you in such a manner.
You can then say something like I don't appreciate the manner in which you speak to me I find it demeaning and uncalled for.
When you can speak to me properly I will answer you.
Keep giving them a pitying smile as you would a naughty child vying for attention
They hate that