My partner is secretly helping his ex with financial problems

Hello and thank you for listening... My partner and I have been together for 1 year and 5 months. Last August, we had a big argument due to the fact that he brought his ex to our place because he told me his ex was too drunk to drive. I expressed my feelings about it and he made a promise not to have any ties or hangups with his ex anymore. Everything has been going well since then. Until recently. I found out that my partner is still helping his ex with his financial problems. At first, he loaned him money last September 2013 so his ex would be out of debt. I was fine with that and I told him it should be the last time, considering my partner told me he felt used by his ex financially. Now, 3 days ago, I saw an IOU note that he lent his ex again $5k, payable within 3 months. It was hidden in his home office. Here are my concerns... I do not want my partner to have anything to do with his ex--I feel jealous and because they only broke up about 1 year and 8 months, I feel that him having contact with his ex is still a bit too fresh. I told him that they both need some time to erase all their emotions towards each other. My other question is--do I have the right to bring this issue with my partner, keeping in mind that I should have not looked around? (I have a trust issue about him secretly seeing his ex and helping him with financial problems and gambling problems. I was only aware of ex's gambling problems because he told me before). I have no problem about my partner helping people but helping an ex with his gambling problem is a big no-no for me. Do I even have the reason to bring up the issue that I found evidence that he is secretly helping his ex financially? Thanks for your advice!

Your partner is not being honest with you and that is now way to have a relationship. You need to tell them that if your relationship is not honest then it is over.