The One with the Sonogram at the End

Plot:

In this episode, Ross finds out that his ex-wife Carol is pregnant with his child. He's stunned to learn she wants to give the baby her and her lesbian lovers last name. Ross and Monica's parents come for dinner which makes Monica really stressed. Rachel decides to return her engagement ring to Barry, the man she left at the alter and learns that he didn't let their honeymoon go to waste. He spent it with her maid of honor Mindy.