A similar conversation in 1998 would have gone a little differently.
Shawn: "You and those damn acronyms... can't you just say 'ha ha that is funny?'"
(it took "lol" and "wtf" a while to become common use, too)
I guess her thought-out-plan is blackmailing her mother.
Let's be honest, saying that sex will be your significant others' only birthday present is a little cheap. Unless he or she would normally pay for it. In which case you're a prostitute, not a lover.
Random person sent a happy birthday greeting to a wrong number, and received back a rather strange reply.