What's your method for holding back?

Ok, so many of you will have previously read, since my wife falling pregnant (Feb 2010) we have only had sex 3 times. The 3rd time was end of Feb 2012. Last night was number 4.:D Both in Feb and last night disaster struck:oops: . I normally go about 25 - 30 days between orgasm and last night I was on day 28. We did our usual fore play but for once this did not work and she brinked and then it went, so was desperate for me to go in. I wanted nothing more then to please her and would not care if I did not cum but it is vitally important that she is fully satisfied. As you can imagine after 28 days I lasted all of a couple of minutes:o which was just enough time for her to start heading towards the edge again. I tried to stop before my brink and ask for permission to cum (which was refused) but even with me pulling out it was too much and I was over the edge.:o The whole process left my wife very frustrated and me knowing that I just don’t have the control I think I do and questioning the whole chastity process.:?:oops::cry: My wife loves me asking for permission to touch her and permission for me to cum but if she refuses I am unintensely cuming anyway. I hate this… Hate it!!!!:x If it makes our sex life worse rather then better why do it…:?:?:? I love the chastity life style but need to find a way to fully satisfy my wife when ever she wants it. HOW DO YOU HOLD BACK?????? Wearers and key holders Ideas please… p.s. she hates any kind of toys so forget extensions, vibrators etc