Title: The three of us.
Word Count: 5k.
Summary: They say two's company, three's a crowd. That you can’t love two people at once, and a relationship is only meant for two. That’s too bad, then. Gwaine’s always had a knack for breaking society’s rules.
Author's Notes: I’ve been meaning to write a Merlin/Arthur/Gwaine fic for ages. I love them as a trio, and the idea of them together, not only sexually, warms my heart. I’ve tried to balance their interactions evenly but you can still expect plenty of Merlin/Arthur. Thanks a million to jelly_1andonly1 for betaing this, it's been awesome working with you. More notes on ao3.