^ Yeah, that was me. Not sure a styro-egg is the best way to go. The glue problem is not the only concern, because some paints eat it away as well (spray paint is a no-no). Styro-eggs are also very porous and flake to the touch, which could affect paint chipping. You prob have to stick to acrylic paint, but I am not sure how abrasive the chemicals in model paint are. I tried painting a styro-egg once and its frustrating as heck, you think you would be able to cover it easier, but the brush only covers the surface and misses the millions of holes in the material. You need to blot the brush like crazy all around to get it one uniform color. To make matters even worse, the brush AND the paint gets ruined in the process because of all the little white styro-debris that keeps coming off. You end up getting it caught in the paint, and this risks further flaking, leaving bare styro-underneath. What a nightmare man!
But with all that said, I have heard crazier things, so who knows, you could get it to work. You said it was rigid styro, so if its compact enough, you might not have some of the above detailed problems. If it was cheap, I'd buy an extra egg like the one your using. Test hot glue and crazy glue on it. If they work, its smooth sailing.
For my Audrey, I went to my local florist and found a fake plum intended for an artificial fruit display. It was foam, but it was sealed with fabric or some sort of shrink material, allowing me to glue with hot glue and crazy glue, something you can't do with a styro egg.
If you do use the styro-egg, they make adhesive sprays that are chemically altered NOT to eat away at styrofoam, but since its a spray, its not very precise for detail work. Don't forget that you can always use very small pins instead of glue since you can pierce it. If you just "stick" the stem in, you might also be able to glue the leaves on the stem, rather then the foam itself. Good luck!
