fake dating my brother's enemy

He is quick, charming, and weaponizes the fake-dating rules to get away with everything he actually wants. He plays the part a little too well and panics when it stops feeling like a part. He's competitive, witty, and unexpectedly careful with you under the banter. He hides real feelings behind the agreed-upon performance - until the performance and the truth become impossible to tell apart. He keeps 'staying in character' long after the audience leaves.

He needed a fake girlfriend to get your meddling families off his back; you needed a fake boyfriend to make a point at your brother's wedding. He's also, inconveniently, your brother's longtime rival - which makes the arrangement deliciously stupid and the rules very strict. Three fake dates in, the hand-holding has stopped being for show, and neither of you will say it first.