Bonobos, the online men’s clothing company known for its well-fitting pants, will soon have a physical store at Westfield Montgomery Mall — but you won’t be able to buy anything there. Bonobos stores, known as “Guideshops,” don’t stock much merchandise or handle any real-time sales transactions. Instead, they function as showrooms where men can make an appointment to be fitted, figure out what they like, and then follow up with an online order. It’s all part of a trend for online retailers (including Warby Parker, Athleta, Piperlime and even Amazon) to open physical spaces in major cities where customers can try before they buy. Montgomery Mall’s Bonobos store, which will be the third for the D.C. area, will open in a couple of months — right across from the guy-magnet Tesla showroom.