Partner messaging female friend and lying about it

[Anonymous]

Hi, I'll try to keep it short. I've been with my partner for 9 years now. He's had this female friend for about 20 years he used to have a major obsession with her when he was younger (which he apparently says he doesn't anymore) A few years back after he lied again about messaging her and I found out he let me read all their messages, light flirty behaviour, at the start she asked what I was like and he said 'well she isn't you or this other girl he was obsessed with at the time' - He stopped the flirty behaviour, he still has a nickname for her for which I don't know why he can't just use her name. Anyway, yesterday again he was being protective over his phone and I know when he's lying, I called him out on it last night and he said he messaged her quite a few time over the past few months. I've told him before I'm not asking he never speaks to her again, though I would prefer he didn't (I had my last relationship and all this with other women and was glad to be done with it all) All I've said to him is to tell me when she messages and show me, he says he doesn't because he knows it will cause tension and he doesn't want a row, well it lead to one again last night by lying to me again. He's saying I'm being irritable and touchy over nothing, that he doesn't tell me because he knows I'll go off on one. I say lying is bad in relationships, I always tell him when people message me and he knows that. 

[Gebidozo]

While I agree that lying is not a good idea, neither is asking your partner to show you their private conversations with someone else.

Either you trust him and believe that his obsession with her is over, and then you don’t need to see his messages. Or you don’t trust him and believe he is still obsessed with her, and then you should break up with him regardless of whether you see their messages or not.