Contact - TUBE FLARING TUBE FLARE ORFS FLARE 37 FLARE 45 FLARE

Season 7. The two learned more about each other and started to grown on one another. Eventually the two comforted each other and slept together, not realizing in a few short months, Meg would be carrying a Nephalem, their unborn child, Cassandra Master.

But then, in 4.04 Metamorphosis , Dean says to Sam: Cas said that if I don't stop you, he will.  That was the first time he ever calls Castiel 'Cas'. And I wonder if it's because he got a bit comfortable with Cas after 4.03 In The Beginning , when Cas laid a hand on his shoulder and gave him a sympathetic look.