Texting is sending short written messages from one phone to another. The verb is 'to text', and texting is its -ing form, used both as an ongoing action ('she is texting her mother') and as a plain noun for the activity ('texting while driving is dangerous'). The verb takes the person as its object with no preposition: you text someone, not text to someone. You can add the message too — 'text me the address', 'he texted her that he was late'. The past is 'texted', two syllables, and yes, it sounds a little odd; some speakers say just 'text' for the past, but 'texted' is the safe written form. Notice how far the word has travelled. It began with SMS, the tiny 160-character messages of old phones, but people now say 'text me' when they mean LINE, WhatsApp, Instagram — any short typed message. Older speakers keep it tied to the phone number; younger ones use it for almost any app. And this is a fine example of a noun becoming a verb: 'text' was only a piece of writing until about 1998, and some careful older writers still dislike the verb, though they have plainly lost that argument.