I bought this jacket because I am sick of only having sloppy jogging jackets to wear when the weather is a little cool. The jacket is beautiful and will be fine for cooler fall weather when a long sleeved tee shirt may not be warm enough but a regular jacket is too much. I think that it will look nice with a long fitted tee underneath but I think it would be too tight to button with anything thicker than that under it, like a sweatshirt. I thought about returning it but I think a larger size may be too bulky across the shoulders in back. The best way I can describe it is it could be perfect for those Autumn days where it's cooler in the mornings but still tee shirt weather in the afternoons. Either that or go a size up if you plan on wearing anything heavier than that underneath.