Seemless shorts from uniqulo are the best! They have many styles.
I find when boy shorts have a trim of lace, that helps with panty lines and ‘riding up’ as well. These are ones that work for me:
They also go a little higher on me…I like underwear that goes above a ‘muffin top’ – these do although that could be because I have a short torso and long legs so I’m no help on the pants.
“Boy shorts don’t work well if one has thighs - they tend to bunch up at the sides.”
The creep up effect happens even on people with skinny hips and thighs if the undies are a size too small. Unfortunately, sizing is by trial and error because undies generally cannot be returned.
I have been wearing the Maidenform boyshorts for a few years under tight fitted pants as well as exercise pants. They come is enough different patterns that I have a bit of variety; I refer to my red pair as my party panties 
Perhaps I’ve never experienced a “true” boy shirt fit. All the boyshorts I’ve tried still leave some butt hanging out, which leaves an awkward butt pouch, which thus my dislike for them was born. Additionally, they ride up. I’d be very surprised if a pair doesn’t rise up on my legs. I’d imagine they’d have to extend a bit down my legs.
I either wear the seamless panties (very rare) or go for a thong (go to). Don’t have a whale tale. Just a nice looking bum.
Those are not true boyshorts. That style is called “hotpants” - yup, the ones with butt hanging out on the sides. Hate that!!! Ditto self-inflicted wedgie aka thongs. 
I mustn’t say I’m going to be a bit more self-aware this week going into work!
I don’t really have a whale tale…Do I?
BTW, if one is prone to UTIs, it might be a good idea to avoid thongs:
http://goaskalice.columbia.edu/answered-questions/thongs-—-do-they-cause-utis-or-yeast-infections
The link didn’t work me, @BunsenBurner.
^^It is a quirk of CC, I guess. Try to copy and paste the entire link in your browser.
I agree with Zeebamom about the Soma vanishing edge panties. Pricy but they have good sales and hold up very well.
Don’t even get me started on underwear. I can’t wear boy shorts. My bum is not only long, but as I’ve gotten older I have sort of a second bit of bum under that. It’s hard to describe unless you have one. It’s like my bum just sort of descends into the back of my legs, and is flat. It’s the most unattractive bum in the world. Only granny panties totally cover it and those are awful. Thus, trousers that don’t hug it are the best. Just fall straight down in the back.
@conmama, did you have any success finding pants?
I haven’t been able to go to Talbots yet. I did find a pair I love at Nordstroms. Fit great in the hips afell nicely in the back. However, they do sit ower on the waist than I normally find comfy, but not too much. They were $80, so I’m not taking the price tags off just yet. If they had been $40 or less I’d keep them. I’ll hopefully get to Talbots Fri.