Russell Wilson -- Crashes Ciara's Girls Night Out ... And She's Smitten

Girls night out isn't for BF's ... unless you're Russell Wilson. TMZ Sports has learned the Seahawks QB surprised Ciara at a fancy steakhouse ... and she could not have been happier. Ciara and two girlfriends were having dinner Saturday night at The Palm -- one of D.C.'s best restaurants -- drinking wine and eating crab ... when Wilson unexpectedly arrived during dinner. Mike Melore told TMZ... "We normally close around 10:30, but we stayed open late for them, until 1:30 AM."