Rut by Reese Morrison

Elias is a viratrix. Which means he’s supposed to be big, strong, and in control. He’s two of those things… but being in control is the last thing he wants.
Especially when his colleague goes into heat, sending him and his best friend, Jordie–another viratrix who just happens to be his research assistant–into rut.
But it’ll be fine. He just won’t look at Jordie’s muscular arms and alluring green tentacles. And he definitely won’t let Jordie get close enough to find out his secret desires…