Milfag here. It's entirely permissible for retirees to wear their medals like this. I've done it on formal occasions.
In the Air Force, it's OK. per AFI 36-2903, Dress and Personal Appearance of Air Force Personnel:
4.4. Wear of Awards and Decorations by Retirees and Honorably Discharged Veterans. Honorably
discharged and retired Air Force members may wear full-size or miniature medals on civilian suits on appropriate occasions such as Memorial Day and Armed Forces Day. Female members may wear full-size or miniature medals on equivalent dress.
Per local custom at my last duty station, if the uniform is mess dress, retirees may wear their decorations. As a practical matter, no one's going to rip the medals off a retiree.