Is there some way I can keep my nostrils from moving?

There is an in office procedure that can stabilize the nostrils so that they don't widen as much with smiling.  If this sounds like the problem you are experiencing, this nostril stabilizing procedure may be beneficial.  Good luck

It is normal for nostrils to move. There are muscles on the side of our nose that cause the nostrils to flare when taking a deep breath. When we smile in addition to flaring, the upward motion of the cheeks brings the nostrils up and out also. This is normal. Botox can sometimes decrease the motion as can the effects of fillers. Sometimes however this can leave a unnatural appearance. The vast majority of us do not interpret flaring nostrils as an ugly feature. When people look at you, most likely they are looking at your eyes and disregard your nose.

Some of the muscles of upper lip attach to the columella and pull down the tip when you smile . This muscle can be treated permanently by surgery and can also be treated with botox injections. Sometimes ala ( nostrils ) muscle moves up excessively due to another muscle . That muscle can be treated with Botox