Christopher Backus who guest starred as Adam, Will's love interest/ prostitute, is married to Mira Sorvino. Sorvino guest starred 12 episodes earlier as Diane, the only woman Will has slept with and Leo's ex-girlfriend.
The cast keep making comments about how much weight Grace has put on. This is a running gag because Debra Messing is very obviously pregnant and is no longer doing anything to hide it.