Sam dropped to his knees first, tongueing Brody's asshole to get it lubed up, already struggling not to change further.
"Mmm..oh...oh shit..come on, Sam! Give it to me!" Brody said, impassioned by Sam's tongue.
Sam complied, hopping up, slamming his wolfish cock into Brody with no more foreplay. Sam pumped madly, driven wild by the tight hole, and driven on by his escalating changes.
Brody's body popped and snapped, the trigger having been fulfilled. Brody's cock grew hard, even as he was being hammered, because he was so aroused by the changes his body was undergoing.
Sam's load exploded, and he fell away, already changing back to his normal form, yet Brody stayed in his normal wolfish form, not having ejaculated yet. The Brody wolf turned to Sam with a loud howl, hovering over him.