Aha, not sexual themed I SWEAR |D ...
Okay, let me explain;

Heart is a dominate male, so he'd make the moves and wouldn't let some one else treat him like a woman uou David is Fire Type whilst Heart is Steel, as when David decided he wanted a kiss, he had a type advantage.
Heart doesn't know what's going on any more.
He's been pinned |D
See not sexual, just David being forceful for something which usually would be fluffy. >u>