ADAPTIVE PANTS Most wheelchair users look for what is called “seated cut“ or “seated profile.“ These will be often tagged as “adaptive clothing.” They will have multiple features to make it easier to get dressed. Stretchy waistband as you noted, but also finger loops inside the waistband to make it easier to pull the pants up. And they will also be cut to be longer in the back and shorter in the front, which looks better when you are seated and is more comfortable. Seamless backs are a really important feature to help Avoid pressure sores. Also no back pockets for the same reason. Some also have wider legs and zippers or Velcro on the side of the leg to access catheter bags. A few have pockets on top of the thigh, which is a really easy place to reach when you are seated in a wheelchair. SPECIFIC BRANDS Here are some brands for men’s pants with adaptive features. Some are pretty expensive, so you may want to wait for a sale. IZ ADAPTIVE: VERY PROFESSIONAL, VERY STYLISH, GREAT DESIGN My favorite brand, but one I don’t buy that often because it is expensive, is Iz Adaptive. Their designer, izzy, was one of the first to design for a seated profile, and she pioneered a lot of design features that other brands later copied. https://izadaptive.com/ The site has a category for men’s “dress pants“ which has several nice options. Some are seated profile, and some are standing profile, so know which you want and read the product descriptions carefully. Personally, I think their charcoal chinos, which are in a different section, “jeans and chinos“ make good dress pants and they cost a lot less than the ones in the dress pants section. I don’t know much about fashion, I guess maybe the materials are different? But anyway, the point is don’t just look in the dress pants section, you might find something else in a different section that works, too. They run 15% off sales two or three times a year, not often. https://izadaptive.com/products/men-game-changer-elastic-waist-chino-pant?variant=46485223473471 TOMMY HILFIGER Ever since they were involved with the Olympics and Paralympics, the Tommy Hilfiger brand has offered a line of adaptive clothing, which looks just like Tommy Hilfiger clothing. Not as many adaptive features as Iz, but they hit the basics. Their list prices are high, but they run a lot of big sales. https://usa.tommy.com/en/tommy-adaptive NO LIMBITS Street style, so I’m not sure most of these will work for what you’re looking for, but great adaptive design. These have those pockets on top of the thighs I was mentioning. The “black wheelchair pant“ might make a good dress pant. Cost is less than the Iz Adaptive dress pants, but a little more than their chinos. Very rarely run sales. https://no-limbits.com/pages/wheelchair-all JC PENNEY ST JOHNS As @South-Presentation 92 noted, JCPenney has adaptive clothes in their regular St. John’s line, which look nice and are about a third less expensive than the other brands I’ve listed so far. I haven’t tried those myself, so if you have any questions about them, ask some of the other users who recommended them. Note that like iz adaptive and Tommy Hilfiger, they have both seated profile and standing profile pants in the adaptive line. (Standing profile adaptive pants will have easy on features, but are cut like regular pants. Seated profile adaptive pants will be higher in the back and lower in the front so you get the right coverage.) so read the product descriptions carefully to know which ones you’re looking at, although you can probably tell from the pictures. They also carry several items in big and tall sizes. And they run a lot of sales. https://www.jcpenney.com/s?searchType=Predictive+Search&searchTerm=adaptive+clothing+men&predSearchTerm=adaptive TARGET GOODFELLOW &COMPANY Target has a house brand of adaptive clothing, Goodfellow and Company, offered at a much lower cost than the other brands, lower even than JCPenney. The designs look good, but I haven’t tried them because they’re made out of “recycled polyester“, whatever that is, and I like at least a blend of cotton or wool. https://www.target.com/c/men-s-adaptive-clothing/-/N-bints They have black jeans in this line which might work as dress pants. https://www.target.com/p/men-s-adaptive-seated-fit-slim-leg-jeans-goodfellow-co-black/-/A-91295420#lnk=sametab if you do try anything from the Goodfellows brand, let us know how your boyfriend likes them. I haven’t yet seen any real customer reviews, it’s a pretty new line. Good luck! 🍀 More on reddit.com

For this year's spring/summer line up, Uniqlo has these elastic band waist pants that look like slacks. I bought 3 and wear them to the office. I don't know if it is available in your country though. Mines is from Japan. More on reddit.com

I'm a big fan of 7 for all mankind... lot of stretch, look good, always fit nice. More on reddit.com