Hiccup finds out | ROTBTD: Friends Crack
In the episode, Ross sees Chandler & Monica making out in their apartment, from his apartment. He runs over and confronts them, etc.
Hiccup: Chandler! Chandler! Chandler, I saw you from the window! I saw what you were doing to my sister, so get out here!
Jack: Well, listen. We've had a good run. What was it four, five months? That's longer than most people have in a lifetime, so goodbye, take care, bye bye then!
Rapunzel: What are you doing?
Jack: Oh, I'm going out on the - something idek xD
Rapunzel: Come on, Chandler, come on. I can handle Ross. Hold on! Oh hey Ross, what's up bro?
Hiccup: What the hell are you doing?!
Merida: What's going on?
Jack: I think, I think. Ross knows about me and Monica.
Flynn: Dude, he's right there!
Hiccup: I thought you were my best friend? This is my sister! My best friend and my sister, I cannot believe this!
Jack: We're not just fooling around, I love her. Okay, I'm in love with her.
Rapunzel: I'm so sorry you had to find out this way. I'm sorry, but it's true, I love him too.
Hiccup: My best friend and my sister! I cannot believe this! Oh, I'm sorry, you guys might wanna get some hugs in too, right? Big news!
Merida: No, no, that's okay, we've actually known for a while.
Hiccup: What? What, you guys knew you- you all knew and you didn't tell me?!
Merida: Well, Ross, we were worried about you. Okay? We didn't know how you were going to react.
Hiccup: You were worried about me? You didn't know how I was gonna react?
Flynn: Okay, alright. Well, whaddya say we all clear out of here and let these two love birds get down to business? Hey, hey, hey, I'm just talking here, he's the one doing your sister!