Actually in every relationship transparency and sharing of secrets are keys to a strong bound leading to better understanding between the two, but when you have a spouse that's somehow judgemental at almost everything, you will surely be unwilling to reveal certain personal things about yourself to them especially gambling that is being vilified by many as something bad.
If you observe that your partner is judgmental, then you have the responsibility of avoiding what he/she doesn't like. Issues like gambling should have been discussed before any commitments, such as dating or marriage, would commence.
I know women give their partners all the support as gamblers. They even follow their husbands to betting shops to support and encourage them. It will be ideal to marry or date someone compatible with you.
Open communication and honesty are important in building good relationship to your other half. That is, if you want to grow your relationship with him or her. Because if you are hiding every time you gamble, it means, sooner or later, he or she will find out and that will cause more issues in your relationship. So better be open about your gambling activity and see where you can meet half way so everyone is happy with the arrangements.