They'd just have to hope that Dean had no other evilly spawned children from one night stands with monsters roaming the Earth. Did Sam need to give him the safe sex talk? No glove, no love, man.
"Shut up. You're older than I am. Not my fault you're turning into a grouch in your old age." Sam managed a smile and picked up his protein bar, throwing it at Dean's face.
"I mean it though, Dean. Even when we're tearing each other apart we've still got each other's backs when it matters. Who else can say they've got someone like that in their lives?"