When you refuse to socialize with vendor reps (because you realize that it’s never really about the socializing), you aren’t home free. You could still end up seeing them in social settings. (“I didn’t know our kids played on the same soccer team!”) Being away from work, your guard will be down. But even if business isn’t discussed, the vendor rep will use the opportunity to build rapport, which may cause your guard to be lowered again in the future. Your best defense is to make sure the rapport goes both ways. As always, be careful of what you say. Vendor reps are great at filing away tidbits of information for use later.