Throw Greg a bone

"Now now," you say calmly. "Let Dad explain himself."

His pants back on, Greg sheepishly walks over. Melanie has her arms crossed over her chest, and a monumentally-pissed-off expression on her face.

"I, uh, well... I just thought you looked so sexy," he begins lamely. "It's been a while, um... You know, and I just couldn't help myself."

That explanation only makes Melanie angrier, so decide to take the reigns: "I think Dad deserves a release too." You put a healthy dose of power into your words. "You should have sex with him."

"Well, I guess... Fine," Melanie sighs. "I'll do something for you when we get home."