The metaphor generally applied to sex using baseball, except towards all things sexting. The bases being:
1st: simple flirting
2nd: a wink
Short-stop: Blatant sexual innuendos
*important note: the sexting bases are almost always cumulative and in the same text themselves.
At first it was just simple flirting, then things progressed and we ended up rounding all the sexting bases; thank you picture phone.