Roger had met up with her for a few minutes in the beginning of the night, but had quickly lost track of her. She had her friends and he had his, though both sets seemed to be getting along perfectly well with one another.
Those closest to him were his Quidditch mates on the Tutshill Tornados, but quite a few Hogwarts alum had shown up as well. It had kept Roger busy for a good portion of the night, until he halfway drunk and determined to find Penny.
He seemingly appeared out of nowhere, as he popped in next to her by the bar. "Now what's the birthday girl doing by herself in middle of a smashing party such as this?" Roger asked, grinning wide at her. When Fred had accused them of flirting, he hadn't been all that off about the observation. At least, Roger had been flirting with Penelope ever since the journals had been introduced and it just wasn't because it was in his personality.
She was attractive, intelligent, and fun to talk with. She, in ways, reminded him of Cho, which might have had something to do with his attraction.