The 3 Clips I missed last time:
00:48 (pointed out by Human fleetingselfconfidence612 & binkothefool2626 )
00:52 (pointed out by Human lizzyserf )
In this Clip its not P.B. but Phlannel Boxingday but in that 2 part episode, its very strongly implied that Phlan is just Princess Bubblegum in disguise. (Speaking German basicly confirms it)
01:03 (pointed out by Human frankienayman3641 )
Last few seconds is Finn Speaking German not Bubblegum but I though it would cool to include that.

Just in Case so this doesn't get claimed as For Kids: fuck fuck fuck fuck fuck fuck fuck fuck fuck fuck fuck

I literally didn't know Bubblegum speaking German was a think until I saw video By _Mezger_:
   • Princess Bubblegum spoke  german 4 ti...  

Clips from Adventure Time:
Season 1 Episode 24 - What Have You Done?
Season 2 Episode 20 - Go With Me
Season 5 Episode 30 - Frost & Fire
Season 5 Episode 34 - The Vault
Season 5 Episode 42 - James
Season 5 Episode 51 - Lemonhope Part 2
Season 6 Episode 42 - Hot Diggity Doom
Season 7 Episode 12 - Checkmate
Season 10Episode 9 - Blenanas