Need urgent assistance--pre-Christmas issues

Hello everyone and happy holidays.

My older sister is happily married with two teenage sons living two hundred miles away, so we do not see each other that often. Here comes the part where I need any of your advice. Last month, I invited the four of them (she, her husband and their two sons) to our place over two hundred miles away for Thanksgiving Day and Friday. Stay two nights and leave Saturday morning. My husband and I thought it would be great to host them since next year they will be traveling to my sister’s in-laws who live in another state for both Thanksgiving and Christmas, so we are having them with us for Thanksgiving and Christmas this year.

I was really quite shocked when the sons and her husband Steve arrived at our home very early Thanksgiving morning as planned (about five hours before we served dinner), and the both of teenage boys were wearing these ugly black old fashion looking Chuck Taylor All-Star sneakers. See these two photos I found online to show you what the two boys came wearing (and had no other pair of shoes to change into):

Imgur

http://www.flickr.com/photos/gayinchucks/1373108405/in/photolist-36kxhR-7XzdQQ-otxuAT-4kSVax-cFvUKu-7AmjLd-98sPcw-8ES8QT-65Qh18-4kWWgC-4kSVar-4kSVBX-4kWWgJ-61ZTeU-aFRQCi-9Ekvog-FsZuY-6aPcmS-obeYhp-68VF4F-ppPowa-oJWLD8-a79jNv-21iR8-hWkGWo-9LesP7-tcYD4-daEdKP-9Eomf1-36kxin-dJTx9C-yoaGb-m35Kb-7QjzNH-95uatq-7PpREb-36kGZZ-3mb66Y-7Bk3Kr-9LbF8r-9LbEXR-5npxm-2Kp2mA-7mxWnB-8TGbTQ-36kxi6-36kxgF-niM7GL-7XtbXF-4Xr2dk
Yes, both kids were dressed nice with khaki pants and a dress shirt, but to wear sneakers to Thanksgiving dinner (with ten other people at our table when I said it was church-attire dress) I was shocked. And her husband Steve was dressed very well, also, except he had on New Balance running shoes, which looked like these:

I thought it looked tacky for the two sons and their dad (my brother-in-law) to come to Thanksgiving dinner at our place wearing old sneakers and running shoes, especially when I told them all that we were expecting dressy/church attire. Anyone agree they showed poor taste in wearing such footwear to a holiday dinner with other invited guests at OUR home??

Also, I really disliked that the oldest of the two teenage boys deliberately came with a super short freshly cut military haircut that was very noticeable. It looked awful as you can see in these two pictures that best show how his freshly cut haircut looked like:

http://howtocuthair.wpengine.netdna-cdn.com/wp-content/uploads/2012/09/IMG_9381.jpg

http://scontent-b.cdninstagram.com/hphotos-xpf1/t51.2885-15/10005623_1440186192902292_1937465304_n.jpg

My husband told me later that night while everyone got situated in their rooms, that he noticed the oldest teenager boy rubbing and feeling the sides and back of his head/haircut, and he asked him why. Kevin told my husband that he just got a haircut the day before, extra short, and was feeling it because it was so short. The other son had his hair longer, nice taper business cut, but Kevin made sure to get a fresh haircut that made him belong in the U.S. Marines.

So I wonder, does anything think I should call my sister tonight before the leave for our place early Christmas morning, to warn/ask/beg to not have the boys wear running shoes and ugly All-Star 1950s looking sneakers and Steve should wear dress shoes not running shoes to dinner at our place Christmas day. Or should I just be happy they are healthy and able to come this year for the holidays, although I wish they would listen to my request of dressy attire, to me that does not mean super skintight bald haircuts and wearing these sort of sneakers:
http://i.ebayimg.com/images/i/120919426909-0-1/s-l1000.jpg

Anyone have advice on what to do–and how to say it to make my feeling known about this with my sister and her husband and teenage sons (15 and 17)?? And by the way, what is so great about these sneakers for teenage boys?? Both of them worn them during the Thanksgiving holiday at our home.

I (and my husband agrees) want Christmas and Friday to be peaceful and nice with my sister’s family, not have them all looking like folks who came straight from a high school pep rally into our home.

Reported for forum change.

Regards,
Shodan

Multiply posted. This one is closed.