About 'bao-ing', each has his own reason for doing that. Its all about subjectivity. Man in general can't be faithful to one and only woman. After some time, our eyes start to wonder elsewhere. Some remain at looking, while others start to take action to lure other women to them. If bao-ing is commercial, i.e. money is involved, it may be simple to break in time to come. I think its more worrying when its all about gam-zheng and no money is involved, at least not at the beginning. Remember the rule of thumb, there is no Reviewee lunch, its either pay now or pay later, usually the later payment will cost more, coz its with accrued interest.