Weird thigh physics glitch whenever there is a bodysuit type outfit

[jiahaoiii3]

Hi guys, I am very new to bodyside in general and I wanted to try my hands on converted uunp outfits to have hdt smp custom body. Ive been successful in most outfits so far, except for any bodysuit outfits. the outfit itself will basically strech to infinity whenever I equip it(see screenshot). I even tried to disable thigh and calf physics in the uunp xml, but the stretching will happens regardless of whether or not the physic is present. I figured it must be the bone weights, but I have no idea where to start.