For a guy wearing a top-hat, Harold sure was skilled at remaining unnoticed. He slipped into the room with all the greasy skill of an eel, and set about investigating the party's food. He didn't want to bother Sally straight out, mainly because he knew she'd be hanging around with Wayne, and birthday or not, Harold and Wayne weren't exactly the closest of friends.
He'd grumble a 'happy birthday' to him when he slipped Wayne his birthday present. A Love Potion; with the hair of a pretty girl he'd seen hanging around in the library. April something...
Either way, the intoxicating power of the love potion would kick Wayne out of whatever shyness it was that possessed him, and he'd kick up the courage to make a move on a girl! That was the plan Harold had in mind at least, who knew how it would turn out...