Back that thing up to me
Closer (ohhhh)
A little closer (work it) This is it but as you have noticed, the other parts have nothing to do with the first one.
I may be a bit late but oh well. Just to clarify, "back that thing up.." has sexual connotations. It's something a guy says to a girl while dancing, or during foreplay. It typically is "back that a**(culo) up.."