For sexting, the images are broken up into 100's = Masturbation/vagina, 200's = topless, 300's = wet/shower, 400's teasing & 500's = specific (for example, Yumiko's posing for Joy or Aly's teen-age pics). When a sext is sent, it is chosen by first picking a random number from 1-4, then choosing the next assigned image in that category. Unfortunately, if you're waiting to get the third teasing pic, you may only get the same shower pic you've already seen. This, and the low number of pics for girls like Joy and Ivy creates the repetition.
My idea was to rearrange the numbers: 100's = specific, 200's = teasing, 300's = wet/shower, 400's = topless, 500's = masturbation/vagina. Then when the sexting starts, have it start at 200 and move upward until it reaches the highest number, then stop. This would eliminate repetition and build to the sexiest pics. Sexts should be sent from 14:30 to 1:30 each day, on the bottom of the hour, since so much happens at the top of the hour. Each girl would need about 15+ pics, 3 for each category (which is a huge amount of work), but a small amount to start would be ok.
Darkhound1 told me he has an idea on how to fix the sexting issue, and I look forward to seeing it.