Small business co-workers have to tolerate a lot of bad behavior, especially since office mates are working in close quarters. But sometimes that behavior crosses the line from annoying to downright wrong. Whether it’s stealing or gossiping, here’s a look at five bad behaviors you should never engage in and why they could torpedo your career:Thievery There’s a reason stealing is against the law and while stealing a co-worker’s credit won’t land you in jail, it certainly won’t win you any fans among your peers. “Taking credit for someone else’s work is pretty common and is not as overt as you may think,” says Joel Garfinkle, author of Getting Ahead: Three Steps to Take Your Career To The Next Level. Whether it’s taking over a project near completion or claiming credit during a meeting, ultimately it leads to employees not trusting the perpetrator. According to Garfinkle, the motivation for stealing credit varies from political maneuvering to making a power play, but either way it turns co-workers off and creates an atmosphere that is less collaborative and less trusting. “It has more of an impact in a small setting because there are less people,” says Garfinkle, noting that in a small company the perception that someone isn’t trustworthy is apt to spread a lot quicker than in a large company.Office InfidelityOffice romances are inevitable since we spend most of our days at work, but it’s a huge ‘no no’ when two married workers are carrying on an office affair. “Either in a corporate setting or smaller office, having an affair is bad and wrong,” says Garfinkle. Regardless of the moral implications, that affair could at best throw your judgment into question and at worst get you fired. People are apt to treat you differently if they know about the affair not to mention gossip about you behind your back. “If you are having an affair with someone at work, people will judge and have a reaction to you based on your value system,” says Garfinkle. If cooling your heels is out of the question, he says to be as discreet as possible. “You want people to see you for your work not your sexual exploits,” says Garfinkle.Constant Complaining & NegativityNobody likes a Debbie Downer nor do they want to hear continuous complaints about pretty much everything during the work day. “It can be hugely destructive to your personal career and the company,” says Jeanne Yocum, founder of the blog Succeeding in Small Business, of complaining and negativity. While the complaints may be justified and the negativity warranted, a bad attitude at work will not only annoy co-workers but could ultimately get you fired. According to Yocrum, a boss will likely try to get to the root cause of the bad behavior, but if it’s simply a personality trait, especially in a small office setting, your days are probably numbered. “You have to realize what you’re doing to the organization and the morale of other people around you,” says Yocum. Bosses can’t let it go on, she says.GossipingGossiping is a fact of life in many office settings, but if you are the person doing the gossiping it will not only undermine your credibility, but it will create negativity with the people you work with. “What happens is it gets back to the person (you’ve been gossiping about) and undermines the relationship with that person,” says Yocum. That’s fine if it’s not someone you work with on a daily basis, but if it’s one of your team members, it could hurt job performance and thus put your job at risk. In a small office setting, the gossiping will likely spread quicker than in a big company, as will the harsh judgment of the gossiper. “If you are viewed as someone that’s a gossiper, co-workers will be less open with you and more skeptical about whatever you say,” says Yocum. “You’ll create a reputation that you’re not trustworthy and you don’t have credibility.”Passing the BuckNothing can be more annoying than a co-worker that won’t own up to mistakes or take his or her share of the blame if something goes wrong. Chances are that person is quick to take credit, but when the going gets tough he or she points a finger. “It’s really bad to blame others and not take responsibility,” says Garfinkle. “People you’re blaming know the truth about the situation.” While throwing your co-workers under the bus may make you look good, keep doing it and it will not only undermine your relationships with your office mates, but eventually the boss will catch on. “A person’s reputation and credibility is really important in an organization,” says Garfinkle.