Sex/relationship

I asked my boyfriend for sex yesterday and he told me he'll think about it. I asked again today and he said we need to work on us and then can think about sex. Mind you we have two kids so our sex life isn't what it used to be. As far as our relationship it isn't perfect and we're working on it. How would you handle this situation?

*edit* : so I asked him what he meant and he said he wants the "old" us back. He's cheated on me twice that I know of and secretly was talking to females through text and POF which I had no clue he had. Being in love, I forgave him and has been trying to trust him. He said he wants to work on our relationship because he's been wanting to marry me. I'm all for working on our relationship, but I also miss the intimacy and he doesn't seem to get it.

UPDATE: We are no longer together, I had him pack his bags because he was verbally abusive last night and punched a hole in my wall and bedroom door. It's time I put myself first and to better myself. Thanks y'all 😊