No btdt either as DS decided to stop himself at 2yo, but the mums I know who continued to 3/4/5 (yes, 5!) all said they talked about it a lot beforehand, with the 3/4yos, they just told them that when it was their birthday, they'd stop, and apparently they were fine with that - kind of like a growing up thing. I think the vacation sounds like a great idea, perhaps DH could plan some special things to do together, now that he's a 'big boy' and make sure he understands that there'll be no more nursing but plenty of snuggles and cuddles and special mummy time when you're back.