Message icon disappeared next to contact on iPhone 4S?

When I go select my dad's contact on my iPhone 4S there's a little blue phone icon next to it, but no little message icon.
I can call him, but he doesn't receive any of my text messages.
Does anyone know why this is?

Thanks!

(P.S. This is NOT my 'Messages' icon on my home screen I'm taking about!)

Did not really see the point