Characters pants being pulled down by the legs?

Hello community. I have been working on this character for awhile now. I modeled the body and clothing separately. Now that I have applied the clothes to the rig strange things are happening. If i move the legs the pants will be pulled down showing the skin beneath. Does anyone know how to fix this? Also the leg is going through the pants. If you know how to fix either of these issues speak up.

The pants probably aren’t properly weight painted to the hips and waist of the character.

However, even with perfect weight painting, your method of moving the body and also moving the pants is going to cause you headaches. Take a tip from the pros, and mask out any part of the body that is covered by clothing. The leg can’t poke through the pants if it’s not there.

Check your weight painting, as Orinoco said.
Regarding the clipping issues: If you don’t want to remove the legs, a shrinkwrap modifier on the pants might help (use the legs as target), the modifier should be below the armature modifier in the stack.