Winona Ryder guest stars as Melissa, former college sorority sister of Rachel (Jennifer Aniston). The air is abuzz with rumors that, back during an extremely drunken frat party, Melissa and Rachel may have shared a not-so-sisterly kiss. A shocked Phoebe (Lisa Kudrow) refuses to believe Rachel's insistence that the scandalous osculation actually took place, obliging Melissa to set Phoebe's mind at ease with the truth. Trouble is, everyone involved was so blitzed on that night that no one can remember exactly what really happened. And in another development, Ross (David Schwimmer) freaks out Chandler (Matthew Perry) with the "celebrity history" of his rented tux. ~ Rovi