The whole dynamic between the Ice King and Princess Bubblegum in 'Adventure Time' is such a fascinating mix of tragic and hilarious. He's constantly trying to 'claim' her as his bride, bursting into her castle with these over-the-top declarations of love, but PB just brushes him off like a pesky fly. What makes it even weirder is that he does this to other princesses too—Marceline, Flame Princess, even Lumpy Space Princess gets his awkward proposals. It's like he's collecting them, but PB is definitely his main obsession. There's this underlying sadness to it though, because you later learn his backstory and how his crown messed with his mind. Makes you kinda pity the guy, even when he's being a creep.
I love how the show plays with the 'damsel in distress' trope by having PB be completely capable of handling herself. She's more annoyed than scared when he kidnaps her, and half the time she's already escaped by the time Finn and Jake show up. The writers really subverted expectations by making the 'villain' a pathetic figure and the 'victim' the most powerful ruler in the land. That contrast is what makes Ooo feel so alive—nothing's ever just black and white.