in pairs
In groups of two individuals or items.
The Third Quartet I made the instruments in pairs - Two different pairs - Violin and viola, and violin and cello. They played very different things from each other all through the whole piece. Elliott Carter
I have got this obsessive compulsive disorder where I have to have everything in a straight line, or everything has to be in pairs. David Beckham
Maybe this is why so many serial killers work in pairs. It's nice not to feel alone in a world full of victims or enemies. Chuck Palahniuk
I think it's a lot harder for the pros to have a long career in ice dance and in pairs. It seems the singles have a little bit of a longer career. Nancy Kerrigan
Wolves don't hunt singly, but always in pairs. The lone wolf was a myth. John Fowles
The needs of the soul can for the most part be listed in pairs of opposites which balance and complete one another. Simone Weil