I am not sure if it has anything to do with maturity. It depends on the breakup, if it is nasty there is no way anyone will want to work together.
I believe the rumours that Aishwarya was physically or perhaps emotionally abused by Sallu. On the sets of Chalte Chalte they had an ugly fight. I highly doubt she will ever want to work with him again and neither would he. Kareena and Hrithik were going to be a part of Shuddhi, until Hrithik dropped out of it, so I don't think they ever had a problem only Suzy didn't want them to work and she couldn't be blamed.
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