In which episode did Joey’s parents appear?

Joey’s parents – Joey Tribbiani, Sr. (played by Robert Costanzo) and Gloria Tribbiani (played by Brenda Vaccaro) make their only appearance; albeit separately in Season 1, Episode 13 – The One with the Boobies.

Friends is an American sitcom where six friends - Rachel, Monica, Phoebe, Joey, Chandler, and Ross share the same apartment complex in Manhattan. It ran for 10 seasons from September 22, 1994, to May 6, 2004. The ensemble cast constitutes Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc, Matthew Perry, and David Schwimmer.

Disclaimer: Brace yourselves. Spoilers ahead!

What causes Joey's father to visit him?

Joey's father visits Midtown Manhattan on some business and stays at Joey’s place. But on their first day together, Joey (played by Matt LeBlanc) learns something shocking. It all starts when Joey finds his father stating words like “I love you” and “I miss you too” on the phone. He intercepts the call to talk to his mother, only to realize that it isn’t her on the other side. Joey is puzzled at first on hearing an unknown voice but soon joins the dots.

A few hours later, his father’s girlfriend – Ronni (played by Lee Garlington), pays a surprise visit to Joey’s place for a completely unrelated reason. She gives back Joey Sr. his wig that he left back at her apartment. Joey Sr suggests she should not board the train home late at night, and instead come with him to a hotel. Joey asks them to stay there so that he can keep an eye on them. Funnily enough, Joey imposes that under his roof they are bound to follow his rules, and cannot sleep in the same room.

Joey sends Ronni to Chandler’s room and asks his father to either break up with Ronni or come clean with his mother. As his father tries to come up with an explanation, Joey uses his bossy house-owner card and tells him “I don’t wanna hear it. Go to my room.”

Related: In what episode of Friends did Rachel see Joey in the shower?

When does Joey's mother visit him?

The next morning, Joey’s mother Gloria arrives at the door to talk to her son. As unexpected as it may seem, she reprimands Joey for asking his father to make things right. She reveals that she knew all along about Joey Sr’s extra-marital affair, and she’s fine with it, as long as it stops his yelling and makes him happy. Joey replies “I don’t mean to be disrespectful, but what the hell are you talking about? What about you?” Her answer to that is hilarious but revelatory. She says “Look honey, in an ideal world there’d be no her and your father would look like Sting.”

She adds that Joey Sr has been more loving and attentive towards Gloria out of shame and guilt, such that she feels like it's their anniversary every day. A confused Joey replies “I’m happy for you?” To which, Gloria sighs “Well, don’t be. Because now everything’s screwed up. I just want it the way it was.” Joey clarifies that he just did what he thought she’d want. In the end, Joey assures her that she’s 10 times prettier, and her wedding ring makes the mistress no match for her.