I'm not sure of the relatives, but it affects the close ones for real. I personally experienced it. Being into gambling I've suffered much and now I've come out partially. At times the loss can't be accepted and our minds won't work as we think. This affects the family and the close ones. They can see the difference and the same makes them down. Atleast to keep our surroundings happy we should have healthy gambling habit with limits.
Gambling addictions doesn't only affect us, I think it affects all family members as your mood around everyonesl is determined by how well your bet went for that day. If you lost money you won't be happy and this will affect those around you and you family members will be among those that'll be affected more. I have seen a family get separated due to gambling addiction. The husband isn't happy when he losses and he blame the spouse every time by abusing her.
When this happens the children will be affected too and they might end up being woman abusers as children learn from the things they see their parents doing. Gambling can be very attractive but we can learn and discipline ourselves so we don't get addicted and spoil the relationship we have with our families and close relatives. Planning with budgeting can help us stay disciplined when gambling.