Twitter Soup - Couple Speak

Why do famous couples air all their private conversations over twitter? See sample below:

ShannaMoakler@trvsbrkr: you look amazing, I luv you baby and I proud of you.

trvsbrkr@ShannaMoakler: Thank u MaMa

I have convinced Chris that we should start doing the same:

Lanalogue@chrissoskin: How could you tape over I Love Money 2? I am so pssed rght nw. Evry time?

chrissoskin@lanalogue: You get dumber by the minute from watching those shows. I don't know y I still luv u.