DDs birthday is coming up and we're currently looking at what do to party wise. We've just received an invitation for another girls party at a play centre on the actual day of DDs birthday (and the day we were hoping to have her party on!) Would I be unreasonable to message the other girls mum, explain the situation and see if she'd be interested in a joint party with is taking on half the costs and responsibilities for it or is that just cheeky and rude. I'm leaning one way, my DH is leaning the other so thought I'd ask here for some unbiased perspective.