jeans clip into shoes

Hi. There is a difference in shape between feet and shoes, naturally your avatar had to wear shoes when you were making these pants.
Append shoes in the scene and adjust the shape of pants with proportional editing to not clip into them. It would be best to transfer weights and uvs from legs+feet combo instead of pants, since yours are longer than maxis ones. Before you do that, join all parts of the pants into one and remove doubles