Somewhere deep in the Quad, a girl pledging one of Penn’s eight Panhellenic sororities opens her dorm room door to find it covered in streamers, balloons, and bright signs bearing her new Greek letters.

It’s Big-Little Week, and the sorority sisters are hard at work to welcome the newest members to their “lineage” or “lin.” A few weeks into the pledging process–the initiation of new sisters, which takes place after they are given their bids–the girls are given a “big,” or a big sister who welcomes them to the lineage (the “little”, big, “grandbig”, and “great-grandbig”). The bigs are also responsible for teaching the littles more about sorority life, the sorority’s traditions, and showering them with love.

Jessica Schwartz, a sister of Alpha Delta Pi, was happy to explain the process by which the littles and bigs (called “Big Diamonds” and “Little Diamonds” as an homage to the sorority’s official gemstone) are matched. “We don’t pick littles–they pick us. We have a speed dating event and they are given a funny powerpoint about all the possible big diamonds. They then have to meet with at least 5 of us for a longer “date” and they can meet with more if they choose. They then rank us through a Google form. We’re given our littles from our new member coordinator and it begins.” Most of Penn’s sororities use a similar process; Alpha Phi calls the potential bigs “Phi Phriends,” Chi Omega calls them “Owl Pals”, after the group’s avian symbol.

Once the girls are matched, the bigs anonymously coordinate times when the girls will be out of their rooms, so they can sneak in, decorate them, and leave them gifts. The sisters contact them in various ways, one of which is by making novelty Facebook accounts for the week (a specialty of Zeta Tau Alpha). These accounts have names like “Dontyou-Mitch Yourlittlewas Hotlike-Mer,” “Watchme Janae-Nae,” and “Deutschyouwishyour Littlewashotlikemine.” They will often post things like photoshopped pictures of the little with Ryan Gosling on the little’s actual profile, and are a fun way for the girls to play with the anonymity of the process (until the reveal, that is). Sometimes, like one submission I received where the big wanted to inform her littles that they were “twins,” the bigs will make videos for the littles.

The bulk of what the girls do is arts and crafts–they hang streamers and balloons, paint canvasses, make signs, and otherwise decorate the heck out of their little’s rooms. They get many of their ideas off of Pinterest, or as Karissa Hand of Zeta Tau Alpha told me, “it’s just tradition really, like remembering what girls did last year because it’s pretty similar from year to year.” The sisters also pass down decorations that they were gifted by their bigs (who may have been received the items from their own bigs, and so forth).

The sisters often give the girls other gifts: serenades from fraternity pledges, manicures, chocolates, and alcohol are common. Kalyb Sims of Alpha Phi’s lineage had a little bit of a different idea: they’ve traditionally sent their littles to a pole dancing class. “Wednesday is sex day for my little because my big did that for me on Wednesday because it’s hump day.”

A part of this that most of the sisters weren’t particularly excited about discussing (but were still willing to) is cost. Some sororities give the girls money to decorate (ADPi gives them a $50 reimbursable budget, for example) and some don’t help with the cost at all. Some girls said they spent around $60, but some spent significantly more–one Delta Delta Delta sister told me that gifts from her big probably totaled around $1,000.