get off with (to get off with = ligar) - also "chat up", "make out with" (US). "Flirt" is what you do BEFORE you "ligas"!
feel up to (to feel up to = sentirse con ánimos para, sentirse con fuerzas para)
go ahead (to go ahead = proceder)
fell apart (to fall apart = romperse, deshacerse, caerse a pedazos)