Question for bulls, stags, and wives

My wife has found someone she is connecting with and they have been on 2 solo dates so far. She is very demi, so is still getting to know him, but they have really been vibing.

Tonight, they are going to go on their third date. I will drop her off at a restaurant, give them some alone time, and then she wants me to meet back up with them after dinner.

I haven't really gotten to know him like she has and she has told me things like "I'm going to be sitting on the same side of the booth as him and you'll be on the other side", "we're probably going to be very touchy Feely with each other", and "don't be surprised if I am draped all over him all night."

We're pretty new to all of this and so this is going to be the first time where I am going to be a part of the interaction. She thinks I am great and has said, "I want you to be your normal witty, charming, charismatic self because when you are your best, it reflects positively on me." I want to do that for her, but I'm not sure I am going to know how to act or what to say in the moment.I don't want to just end up sitting thee watching... I want to make it feel "normal" for them, but I'm afraid I'm going to be awkward.

Being that it is going to be at a restaurant /bar, do you all have any advice on how to try and carry on a conversation while all of that is going on? Is there anything I can say or do that would help both him and her feel comfortable to continue touching and doing things, while all three of us are engaged in conversation?