Do I stand my ground with my boyfriend or let it go?

[Katie]

When my boyfriend and I were in a break he started blogging poems about another girl, they were very deep and beautiful and he was basically saying he was in love with her.

We got back together about a month and a half ago and its been lovely but a couple of weeks ago the blog came up in conversation during a tipsy conversation leading to me almost crying about it- he explained how he didn't mean what he was writing and said he would delete it for me.

Today I came across the blog and he hasn't deleted anything, it upset me so I mentioned in a text, that I was being serious about liking him to delete it and that it's not fair to say he'd do something and then not do it. I was very nice but he never replied.. Now I'm sitting here wondering why? He's been on fb and twitter..
He will text me in the morning saying he fell asleep or something, I don't know whether to stand my ground and say look delete it.. Or if I should just leave it. I don't want to let him walk all over me because that shouldn't be a thing, he should consider my feelings. What should I say in the morning?