When a scenario. situation, or object is either:
1. Large in size (like the RMS Titanic)
2. Sad (like the sinking of the Titanic)
3. Romantic (like the 1997 film 'Titanic')
1)
Guy 1: Dude, this burger is huge!
Guy 2: Woah, so Titanic!
2)
Guy 1: Got back from the vet, my dog is really sick.
Guy 2: Ah shit, that's so Titanic dude, I'm sorry.
3)
Guy 1: I took my girl to the beach and we held hands and walked in the surf.
Guy 2: You homo, that's so Titanic.