Brother Dear Series by Gerald Ockham

Kit Smith is recently dumped, gainfully employed as an associate college professor, and proud of his working class roots and what he's made of himself and his life. Why would he need to go seek out the company of his one-time step-brother, Rowan – rich, straight, blue-blooded, bigoted and unhelpful, the bane of his life during their shared adolescence?

A faculty party, catered on the cheap, is bad enough by itself, associate professor Kit thinks. Add to that, one hot, disagreeable step-brother, and a drunk hetero best bud who's up for anything – including making bets regarding Kit's sex-life – and things can only get worse. ..

Kit really shouldn't have been planning to make his ex-boyfriend jealous. Especially not with his bull-headed, infuriating step-brother Rowan. Especially since Will isn't as dumb as all that, and Kit's been caught out. And now Will wants to turn the plan upside down, and to make Rowan jealous, instead. .. Kit has a feeling this is all going to turn out very badly indeed. .. . Especially for him.

Oh, what a disastrous faculty party. For Kit especially. .. What a fool he feels now, trying to make his awful ex Wiliam jealous. And with his obnoxious stepbrother Rowan, of all people! But maybe the situation can be salvaged. And maybe Rowan's not so awful after all. ..