Hi and welcome
I wish that I could ease your mind, but I just don't know if something is going on with your husband and this girl, or not.
Maybe he told you that it was a long time ago, so that you wouldn't worry about it. I suppose that this is a possibility.
However, you know that they were an item until only a few years ago. And ~ have I read this correctly ~ they spent a night together on his recent trip home? But it was supposedly just an innocent thing?
And the 'love letter' e-mails ~ they were from the past, before you knew him? Have I understood that correctly?
(If they are so old, how come you just found them?)
If my husband spent the night with an old flame, which he didn't wish to talk about, then I would be feeling upset & confused too, but it may be that it really was innocent.
The old e-mails are your proof that they were very close in the past ~ despite what he says ~ but he is married to you now, so your real concern is whether something is still going on.
Presumably he doesn't see her ~ he is with you ~ so maybe he is being faithful to the marriage and just spent some time reminiscing.
You say that you 'are very much in love'. If he does really love you and you love him you, then you should be able to trust each other. Has a trust issue arisen before?
You also say 'I got him his papers by us getting married' ~ do you think that this is relevant to what is going on ~ if anything is?
I don't know, but I can understand you being very concerned that your husband spent a night with his ex. You need to know the truth, but hassling him to talk may just cause (unnecessary) arguments. And telling him you went through his e-mails might, too.
I don't know, but you do need to sort this out.
Maybe someone else will have some ideas.
Good luck.
