Help Big question with texting

[npiper87]

So every time i try and send a text to my girl, it wants to make the message a MMS and send to some att link (mms.att.net) and i have no idea why. why can't i just do regular text messages with her like i do with my other friends. she has iPhone 4 S now, and my friend has iPhone 4 and it sends fine to him. and she gets texts fine from other people. its just me?whyyy??