I love these new overalls from Jaded Gypsy! So durn cute-umous! You can detach the straps from the pants and just wear them as jeans too! The straps are adustable.
THESE ARE VERY OVERSIZED! I would say even an XL could wear the SM/MD but it depends on how baggy or loose fitting  you like them!  There is also a small stretch of elastic in the center of the back.