It's his turn to have the pullover, you know that.
You have quite a few options, such as V-neck dress shirts, button down shirts in fine materials and, in cool weather, cardigans and pullover sweaters.
During the winter, you want a coat that is roomy enough to accommodate a pullover sweater underneath, yet still fitted enough to look flattering without anything bulky beneath.
A dress vest is typically designed with buttons down the front, as opposed to the more casual pullover style (which is often a feature of sweater vests).
If you're sporting a red pullover over a white, collared shirt, wearing a skinny red belt over your sweater is a chic, sophisticated way to accessorize an outfit while maintaining a flattering visual line.