I did receive texts around dinner time which to me felt like I was being guilt tripped. Why don't you want me over tonight? I've done nothing wrong. You're always so sensitive etc
Oh @droopyears I do feel for yo. You're obviously very fond of this man, and I totally understand the joys and good things about a non-live in partner (it's my ideal, too).
Could you be a bit assertive about this? Do your normal shopping for you & your 2 DCs. Keep a record of how much that costs.
Then do a calculation of how much extra you have to buy for your notsoDP - or the day on which your normal food shop runs out because of his eating and snacking. Add to that a proportion f the daily cost of energy (heating, lighting, hot water etc).
Show him that he's NOT pulling his weight.
Or start the conversation about him moving in, and the necessary rearrangements of finances that would involve eg paying more Council tax, him paying you rent, or him paying a third of utility bills etc.
See what he says about that, and take it from there ...
It sounds like he's actually moved in without your permission, and he's assumed that you'll look after him as no doubt his mother does.
He needs to engage with reality like a grown up. I'm sure you can find a way to do this calmly and kindly, but firmly 