The Hot Patterns Body Suit reminds me of a body suit I wore in 7th grade. The virtue of this 'suit' is that I can wear it under low cut waistbands, and the skin will not show! (The HotPatterns people say it helps avoid the dreaded "muffin top" but I disagree...it does not "avoid" the muffin - just covers it!)
Below are two of my versions.
Note! I'm EDITING this on January 11, to answer some your questions about the crotch snaps and overall comfort level when wearing this.
I find these very comfortable to wear, and I have to say that when I made the first one, I was doing it on a lark...I really didn't expect it to be that comfortable. BUT, they ARE comfortable, and I think the following is why:
I installed the snaps so that the 'nipple' of the snaps are pointing away from my body. Also, the pattern is designed so that the snap closure is toward the back...and there is no way to put this delicately...the snaps are right under where the cleft of the butt cheeks begin. Since there is a natural hollow in the body there, I find that this placement is super comfortable. At no time do I feel the snaps when wearing.
I sewed the snaps in. I did not use snap tape because the only tape I could find was cotton twill, and thick. I even checked out the garment district in NYC looking for softer snap tape. I did find some, but the snaps were very large. And the other tape I found, at a 'dance wear' notions place, was hook and eye. That would have worked, but I wanted to use snaps. The first version had five snaps, and it was a PITA to sew all the snaps on. So the next version used only three (larger) snaps, and that worked well.
To help me hold the snaps in place while sewing, I used "505" temporary adhesive spray. I just put it on the back of the snaps, then placed them where I wanted. It worked very well.
The "boy" short bottom does not ride up, even in my tight fitting low cut jeans. Part of the reason for this is the way I installed the leg elastic. At a 1:1 ratio at the front of the leg, then stretching slightly in the crotch area, then stretching a LOT under the butt cheek, where it meets the leg. This creates a 'cup' and is comfortable, and the leg does not ride up.
I hope this additional info helps!