Hi I was wondering, can subspecies conceive of spring?

I just saw my yearling male Thamnophis eques vergatenius lock with my adult female Thamnophis sirtalis infernalis.
I have my 2 couples garter snakes housed together in one cage.
The vergatenuis are yearlings and my infernalises are adults.

Because my adult male infernalis is a lazy bum and not in the slightest interested in the female, and the young vergatenuis is all over her.
My female has just shed and now they are locked.

Does anyone know more about this?