Son is blowing all his savings

My son is 24. He’s got an ok job. He takes a lot of extra work because he wants to move out. I support him moving out .It’s definitely time. But twice now he’s had enough money saved up to cover the deposit and rent on a place he’s looked at ,and him and his gf has blown it all on fancy hotel stays & shopping trips .

My son’s now desperate to move out in a couple of months, I’ve told him he can stay here as long as he wants but i totally get why he wants his own. His gf is moving in with him when he gets his own place . Shes never had a job , keep coming up with new ideas what she wants to do. I get it she’s young. They don’t need to have it all figured out. But it’ll be my son who pays for everything and that’s his business . I just don’t see him ever be able to move out because he keeps blowing money on these huge romantic gestures. The amount of money he spends on flower arrangements monthly is gastronomical.

My sons super stressed because he just got his paycheck and he didn’t make as much as he expected because he took time off to spend with his gf . Somethings not clicking. He was also about to send a huge amount of money to an overseas landlord , til I realized it was a scam.

I’ve tried to talk to him. But he wants to be able to do everything by himself. I’m also worried that if they do move in together they won’t keep up with rent and bills because they think it’s normal for couples to go on weekend trips to Paris etc.

I know I just need to let him fails but we’re talking alot of money here. Her parents are a lot more financially set than me. I’m a single parent I’ve been chronically ill for several years now so I can’t help out as much financially as I want to. I know her dad wants her to support herself. She gets an allowance but according to my son that’s mainly for personal needs such as clothes skin care.

How do I tell him to stop spending money right now without it sounding like I’m not being supportive? He’s very grumpy because all his savings are gone. I’m sorry this was so long.