This may come as a surprise for you but text messages containing flirty or sexually explicit chats may just be taken as an evidence of you having an affair. Wives may happen to retrieve these things from your cell phone. Text messages may disappear like oral conversation or may be permanently stored somewhere for potential retrieval like emails. If your device is more akin to email than text messaging then messages are stored. This type of plan would require some people to have a sound message only account. Some providers keeps text messages for up to 72 hours until delivery is successful. If a message can't be delivered then it is automatically removed from the system with no option for possible retrieval like it's lost forever. But if you have stored them in your phone or on your recipient's phone it may not stay long on the network for a long period but may be accidentally retrieved by wifey. Smile... you need not hurt somebody by having an extra marital affair. Just be honest and tell her you want to end the marriage and be free. To be fair when you free someone it means she has the full option to seek a good lasting relationship to grow old with. Have you got the one who will take care of you when you're sick and not just the money? Think of what you are doing again. Some things last forever: love and commitment.
Reference: http://news.yahoo.com/s/ap/20080126/ap_on_hi_te/text_messaging_privacy