I know a lot of women irl that are in relationships with guys like Lee. The women want babies and the men just go along with it because ‘okay I guess’. And obviously they love their children, they care for their gf’s etc. But there’s a big difference between that and actively choosing to be a partner and a parent imo.
I ofcourse don’t know Lee so can only speculate. But he was a thirty something guy living at home and working as a delivery driver, nothing wrong with any of that but then in comes bouncing Grace with her “cool” influencer career, and she wants to share all the perks of that with you, help promote your music, secure you paid influencing opportunities of your own! Plus you get to move into a flat with her, and out of your family house and feel like a grown man.
I feel like Grace was 100% the driving force behind them having the first baby and the second one. You can see in her body language with him and the way she talks about him (plus how he’d come across in her. vlogs) that she’s much more obsessed with this relationship than he ever was. And look at the way Grace talks about things, she never says ‘me and Lee decided xyz or me and Lee have discussed blah blah’ it’s always just her.
And imo him not proposing is one of the biggest signs he’s not committed to their relationship. Ofcourse marriage doesn’t mean everything, but Grace is desperate for it and VERY vocal about that, Lee is obviously not against marriage as a concept, he has told her over and over again he intends to in the future. But year after year rolls by and nothing. He’s been with Grace for years, marriage is something he obviously sees for himself in the future, they have a child and another on the way and still nothing? That tells me that while this situation works for him now, he doesn’t see Grace as his actual life partner and he’s still quietly keeping his options open.
With Lee I have never seen any clear intentions from him. It’s always Grace talking about how they’re soulmates with him awkwardly nodding along. It’s always Grace gushing about her pregnancies and kids and what she wants for the future with him just being … there? Even meeting on bumble is interesting because she would’ve had to be the one who made the first move. Their whole dynamic seems unbalanced imo. I predict they’ll be broken up in the next 3 years.
she has a partner, mum and sister she palms her kid off to on a regular basis plus a cleaner and a minimal workload flexible job she can do around childcare she practically has a whole town! 
