As Mark finishes shooting his load all over the basement floor, he notices something different about his own cock and balls. The fat mushroom head of his prick has become a little more pointed at the end, and his entire cock is taking on a deep crimson color. As Cal finishes planting his doggie seed deep in Mark’s gut, Mark watches the pubes on his nuts change to a soft golden fur and the base of his cock begins to swell into a knot. The skin around the base of the knot is becoming fur covered as well and forming into a sheath attached to his belly.
“Holy crap!” Mark exclaims. “You’re changing me too!”
Cal lets out a low growl as Mark tries to pull away. Cal’s knot is still lodged tight in Mark’s hole, and Cal gently grips the back of Mark’s neck with his teeth to let him know that he’s not going anywhere soon.
Mark can still feel Cal’s cock pulse in his ass as Cal's knot begins to shrink. Mark's changes seem to have stopped, but his dick is clearly no longer human.