DH used to ask me to hem his jeans. I complained and complained, but he insisted that since I hemmed my own, I should be able to hem his. I finally explained to him that men's jeans come in lengths with 1" increments. Women's jeans don't, and I'm short, so I need to hem my own. He should buy his in the right length! Since then, that's what he does. If they don't have the right length, he has to keep shopping till he finds them.

Anyway, I hope you can get your problem solved by either figuring out how to do them or returning them with a polite explanation. If you do them yourself, be sure to use the correct needle in your machine. I think there are ones designed for jeans.

Clearly you've started one pair already. If you want, return the jeans to the person and say "I tried. However, hemming jeans and sewing/piecing/quilting are NOT the same. I'm sure there's a tailor in town you can bring the rest of the jeans to. This is where I go for my tailoring needs..." or "I do not make alterations. I'm not a tailor. This is where we go..."

I feel for you. I hem pants (jeans), all the time. What I found works the best for me is I do it just like a tailor would. I measure the inseam (not ALL pants are the same, some times they are shorter on one leg - BUT the inseam on someone is always the same), then I measure the inseam on the jeans and then add extra for turning under. I've marked the spot that will end up being the bottom of the hem, this way I get my folds and I can iron my folds. This has never failed me and I hem 8 or 10 pairs of pants a week. Good luck

I don't mind doing it, actually. I have several friends that I've offered to do it for, as they don't sew, its so expensive to have it done, and they really appreciate it. Each time we go visit our kids (they live in another state), I always have several things to alter, too, as I remind them ahead of time to go through their things for repairs, hems, etc. It's an act of love for me to do it for friends & family and I love sewing, in all forms. I can work on the items as I'm visiting or watching a movie.

With pant hems, I prefer to pin the pants in the front and back while the person is wearing it with the shoes they'd wear. The front of the pants hem should be slightly shorter than the back of the pants hem so that the pants hang properly and don't bunch up at the front of the shoes. There are some great video's online that show a quick way to hem jeans, which I'll remember the next time I hem jeans as I like how they turn out. There is always something new to learn, and I love that!

Here you go. This is it! This is the truth after all, so no harm done. Except maybe to his wallet...and why didn't he buy them in the right length to begin with?

I guess my answer that "I am a quilter, not a tailor" serves me well when I get these requests. I waited years to own a really nice quilting machine, and am just not willing to use it for sewing repairs, when I could be making something fun. I used to just name a crazy piece rate, but too many took me up on it.
I am a I short, fat, person and I can buy jeans the right length. If I can, they can. Lord knows with all the brands of jeans out there, they could do a better job of finding their own size.
I guess I just think life is too short to waste it doing things I hate. I do repairs for DH, but he repays me a thousand times I a day, so I don't mind.
Feel free to use my line if you like.