Reconciling After Divorce

I have a Sim called Shreen and she was dating a townie but I split them up so Shreen could date Solo (my first Sim) and they had the chemistry for a full on relationship. A little later Shreen met up with the townie at one of the discos and I totally forgot they once dated till I saw the 'love' var was full red. A little chat and flirting finally got rid of the red. But even after the red has gone the townie will flirt quite happily and do all the romantic flirty poses and sounds but the moment Shreen goes for a kiss the townie stops her. I keep trying everytime they meet to get them to kiss and date woohoo but the townie only responds to flirting but never lets Shreen kiss her. I've given up trying to get them together now!
Wonderful that the game holds grudges and memories of the pain the break up caused.