What you are using is a predictive input based on a dictionary. You
just
enter one key per letter and the phone guesses what you mean. I do not
knowyour handset but there is a key that you can use to cycle the
possiblewords that fit what you type. There most likely is also a
way to break the word without entering a space. You can also turn the
predictive  input off if you like the traditional way. Check the
manual for details.

In general predictive input is good but at least the phones I have used
handle poorly the case where the word is not in the dictionary. You
need to retype the whole word in the traditional way.

It may be that the word "sexy" is not in the dictionary - possibly to
avoid lawsuits from parental rights organizations. If yuo need it often
you can add it to the dictionary. Or you cantype just sex then break
and press the y separately

Osmo