From a spam analyst's point-of-view, little "cute-sie wootsie" comments in emails are not really all that amusing. What do I mean by "cute-sie wootsie?" I mean things that are not real words but are meant to convey a certain meaning by avoiding all proper rules of grammar.
Examples are including things like "mmmmmmmmmmmm" in the subject line of an email. What is that supposed to mean? People do it all the time, as well as putting things like "Guess what I'm up to......................................................." with lots and lots of dots and periods. People are trying to be cute by putting stuff like that in their messages but let me tell you, from an anti-spammer standpoint those little cutie conventions are more likely to get your message flagged as spam than they will humour the end recipient.
Spammers employ tactics like that all the time in an attempt to bypass filters. They love to repeat letters or put periods in subject lines. My advice to people is to not put stuff like that in there. Another common subject line with people trying to be cute is putting a smiley face in the subject lines of their emails instead of actual words. Don't do that, spammers do that on a very regular basis. Besides which, putting smiley faces in an email subject is just plain-old bad form. A subject line is supposed to convey information about an email, a smiley face gives nothing (or rather, nothing useful). Don't do that, either.
Finally, my last example of "cute-sie-ese" is adding extra letters to the end of a word. Recently, I came across a false positive with the subject line "I'm freeeeeeeeeeeee!" Spammers, as part of their tricks, regularly employ the use of extra letters in an attempt to bypass filters, but putting extra an extra 'e' on the word 'free' is an especially bad choice. Spammers love to advertise to people on how to become financially freee, or financially fr.ee, or financially f*r*e*e*. Adding extra letters like this just makes filters suspect you are a spammer, so I would advise not doing it. Don't try to be too cute in an email, especially if you avoid following the basic rules of English grammar.