It's the Liza Minelli Effect. And given the resemblance they could be her sons.
What sets off even my unattenuated gaydar is whenever one shows off his dance moves, usually punctuated by high kicks with those long, limber, Hugh Jackman-esque legs.
I like them but not their work - like a lot of HGTV decor hosts I can pick their renovations out of a lineup because they always look the same (like that "ship lathe" "Fixer Upper" couple), as if ordered out of the same catalog and warehouse, trendy, but also with no regard for keeping signature detail. Example: their work on ranch homes in Austin, which typically still sport their original beautiful, mid century modern white keystone facades with matching interior fireplaces, where the first element of their design is to break up that continuity by resurfacing over the fireplace keystone with plaster, polished stone slabs or stone patterns available in every Home Depot in America (which coincidentally is also the "upgrade" first rejected when they go over budget). I swear, if I see them design one more kitchen backsplash or shower enclosure with glass pencil tile I'm gonna hurl.