That was not the sort of reaction one generally wanted when they kissed someone. They wanted to be kissed back, not pulled away from. And even if Lyle explained himself before he leaned in to kiss him back, it had already spoiled the moment.
So Nico was the one to pull away this time, a scowl present upon his lips as he remarked, "Then just forget it." And then he tried to dismiss his own displeasure by remarking, "You need to check on the quiche anyway and I..." He hesitated, trying to think of something. "Have to go check on the plants." Right. That worked. And he pulled away to go and do just that.