Perhaps the most versatile phrase ever to appear on urban dictionary ever. It can be used in many many situations and contexts but its main uses are:
1. To be
well in with someone - ie being in a relationship, or in someone's favour
2. Getting well in - can mean trying to start a relationship, pulling a bird, or getting to any of the 'bases' with anyone.
3."
WELL IN!" as an exclamation - can be used either as an expression of success or celebration (ie an alternative to 'YES!') or used to indicate when a friend or associate is 'getting well
in', usually in conjunction with a
sharp elbow prod.