Lumber up 

The act of getting a penile erection.

'Hey Bob, this road kill... its still warm!'

'Time to lumber up boy!'

'Bob, this roadkill...its still warm!'
'Lumber up boy! Time to become a man!'

Lumber up by Bearforce1 December 17, 2014

Limber UP

1. (Sports) to exercise in order to be limber and agile
2. to make yourself flexible

You gotta limber up
Means: you gotta get more agile :

Limber UP by Nimsz January 9, 2010