My friend is engaged to be married, she doesn't have any children yet but is step parent to her fiancé's DS and they're also TTC.
Friend has fallen out with her fiance tonight because she heard from a third party that her fiance is giving his ex ÂŁ400 so she can take their son on holiday with her, and he kept her in the dark about it.
Her fiance then lied about the amount he was giving his ex when my friend finally asked him about it, he told her he was giving ÂŁ200.
Friend asked the ex how much he was giving and the ex said no its ÂŁ400.
Friend asked fiance why he'd lied and he said it was because he knew she'd check up on him 
Friends fiance said its nothing to do with her what he gives for his son, but he didn't think its fair for his son to miss out on another holiday because his mum couldn't afford to take him (she recently went on a different holiday and left her DS behind to stay with his dad and my friend) and if friends fiance wasn't going to pay for his DS to go with his mum then she wasn't going to take him, apparently when deciding whether she can afford a holiday she doesn't factor in her DS..
Who, if anybody, is being unreasonable?