Thank you all so much for the messages 
I have not had internet access for a couple of days and youngest was in hospital with a virus, but ok now, thankfully.
Witchinthewindows I don't know if there is a way you can see all deleted texts, I have heard of it but don;t know how to go about it.
Whenwillifeelnormal
I think I have recently (past few months) realised that he will never change , HE will always come first and despite his "I'll try" s to shut me up he will continue to blithely do as he pleases with no regard to family at all, and there will always be an excuse to him
. That and the fact he is never around anyway the past few months so there is nothing good to miss, however small, iyswim?
Do you think the stopping initiating sex with me is significant? Until a couple of months ago he would always ask me for sex even if we were arguing a lot at the time, but now he never does.
No he's on PAYG, no contract, phone not even registered. I've checked both phone and SIM memories on phone yes.
He obviously thinks he is being really clever just by deleting texts but he forgot to delete the message counter so I can see that say 8 texts have added on that day, but he didn't text me, and he definately wouldn't be texting his parents back and forward that many times!
No, no suspected OW, but he is a taxi driver so it would be easy to meet someone I suppose. I meant that sometimes I have an inkling he is sitting at his friends houses or in pub whilst I am struggling with the kids bathing/dinner/bedtime - he will say he is "working" so there's nothing he can do, but a good few times in the past I have later bumped into one of his friends and they have said "It was good to see B for dinner the other night" or something !
or I have seen the messages on his phone arranging to go over to friends whilst I'm clearly run ragged after working all day and 3 kids to feed, bath and bed! Sorry should have been clearer about that, but the texts to friends are not deleted (he thinks I haven't looked) and obviously he isn't at friends every single night?
Have looked through his wardrobe and the car for another phone but nada. He still has a room at his parents with his stuff still there from before he moved out although his mum has filled it with kids stuff too. He does have a key to his parents though and goes up every day to pick up DS. I've had a quick look in that room but hard when his mum is around.
If he does keep fuel receipts I don't know where, and he doesn't earn enough for VAT.
It is very exhausting
. I did suggest to him last night that it would perhaps be better if we just co-parented DS but not be together as I just can't take any more. He said "Where would you be without me then eh?" to which I replied "The exact same since you do clearly play no part anyway of your own choice". He didn't like that and text me that he would have DS living with him
and later text "If you want to end this you have my consent but I will not be moving out"
giant sigh <
sorry for giant post.
I'm going to do the PI trick which atswimtwolengths suggested and keep checking the phone. But it looks like we will be breaking up in the new year anyway so you are right it does seem a moot point but I would desperately like to find out about the details of any affair so he can't smugly get away with it and paint himself in a great light to everyone.