So am just curious to know if these little games are the one's that got to him or already developed such habit and to know if possible that the practice will continue elsewhere after leaving there when he lost the money and to look for means through gambling to recover it.
It made me remind an experient where people were asked to do a test or set of activities without any rewards involved on the process. So they did it without any changes of mood, as they do trivial tasks on their daily routines. However, right after they were asked to do the same set of activities, but aware that they would be a financial ($) reward involved in the end of the process for the most skilled people in such tests. For that reason, they moods completely changed and they took the tasks very seriously. It wasn't a trivial thing anymore.
The same must happen regards the friendly games you mentioned. While there weren't any rewards involved, people would take such games friendly, as usual. But when rewards were introduced to the most skilled players, people got very competitive instantly, because they had to overcome their friends (who became their rivals now), otherwise they wouldn't win anything in the end. For me it seems an automatic and primitive behavior displayed, because it should be obvious for reasonable individuals that the friendship should be above every and any financial rewards in this case...