Colin was a little confused by the fact that Zach kept pushing up into his nails. It must be one of those unconscious reactions. It didn't mean that's what Zach wanted exactly. No. He would be sure not to do anything that would really hurt his boyfriend. He could be sure to pull back just a little so as to keep Zach from getting harmed.
Zach's legs around his waist made him smile a little. He liked the way that felt, the way he felt. He made a small noise, nibbling a little at his boyfriend's lower lip.