In other to make your marriage last it is important we don't hide anything from our partner and I think even before we get married it is important we let our partner know our gambling habit because some people don't like people that gamble not to talk of getting married to someone that love gambling, if you don't disclose it to your partner surely he or she will fine out one day and when they do they may not want to continue the marriage anymore and in other for them to stay they will give you a condition that you should stop gambling and I'm sure it will be difficult for you so it's better you tell them everything about your self even your gambling habit they have the right to know it.

Yes gambling has the capacity to break marriage or a family, just like I said above if you don't tell your partner your gambling habit and he or she finds out they may decide not to continue with the marriage especially if they are the kind of people that hate gambling.
And again if you are addicted to gambling your partner may decide to divorce you because of your addition to gambling, I have seen someone that his wife divorced because he was so addicted to gambling that he started selling his property.