Even if he came home right now saying he was sorry and it was all a terrible mistake i dont see how it would ever be right again , the man you thought you knew has gone , and this selfish idiot is now your husband. I bet you dont love this version , but this is who he is now , and you might have even seen glimpses of this selfishness in the past.
I honestly understand the financial stuff , but all that can be sorted , you can go interest only on your mortgage for a while and theres loads of other stuff you can do . I really think you need to tell him to leave . Hes taking the piss big time .
Id have his bags packed for when he comes back and id tell him to fuck off out and go and live with her . Her kids arent your problem , him planning to move in and when isnt your problem , your problem is you and your kids .
I also think , that if you are really wanting to save this marriage and for him to realise what a terrible mistake hes made , hes got to go . Hes got to go and suffer all the horrible consequences and not be able to see you anymore ect . Hes got to be able to see that this woman isnt all he thinks she is and that it just wasnt worth it . Only then will he be able to see what hes done . Hes probably like a drug addict at the moment and cannot see what hes doing .
The other option is that he stays , gets the best of both worlds and maybe things fizzle out with the ow . In the meantime he will blame you and resent you for " spoiling his fun ".
The fact he hasnt yet gone to me is a positive and id interpretatre that as hes not 100 per cent sure about her . Id force the issue , id *make" him move in with her , see if shes just as loveley with a bunch of kids round her neck , a pissed off ex husband and the social embarresment of what theyve done .
He obviously sees her in a flawless love struck way. Fuck that , have him use the toilet straight after her after shes done a huge dump , have him wake up next to her smelling her morning breath and have her washing his skiddy boxers and smelling his farts .
This sounds like an absurd fantasy on both their parts , and id shatter it .