Kate has this lovely habit of blowing raspberries when she has a mouth full of food

It basically flies everywhere- all over me, all over her highchair, all over the floor and all over herself. I've taken to wearing an apron during feeds! Shes been doing it for about a month now- Charlotte never did it so I'm not quite sure how long I'm going to have to put up with it. I try not to react to it (which can be hard when you've just got a face full) but if any other babies have gone through this phase- how long can I expect it to last?
Shes been blowing raspberries for months (she does it constantly all day!) but only just started it with her mouth full about a month ago- she does the whole way through the feed, even when shes really hungry so I don't think theres much I can do about it, she must just like the feeling.