The 13th step is when a member of a 12-step group who is well established in recovery makes sexual advances on a new member. This is strongly discouraged but does happen occasionally. 12-step groups are informal and any regulation must come from the members themselves. Some group cultures are more permissive than others, and unless someone does something illegal, there’s really no one to appeal to. As a result, 13th stepping is sometimes a problem.
The problem with 13th stepping is that people who come to 12-step meetings are looking for help. They are often in a bad place and vulnerable. Not only that, they’re new. Someone with a decent stretch of sober time, who is well established in the group, is on firmer ground. Although the offending person doesn’t have authority over the newcomer, he–or she–is still exploiting a power differential.
The result of applying this kind of leverage is almost always bad. Either his advances are successful and the newcomer enters a romantic relationship–a dubious one, at that–at the worst possible time, or the newcomer rejects the advance and feels uncomfortable at future meetings, if there are any. Deciding to attend a 12-step meeting is difficult enough. One bad experience like that may convince her to drop the idea completely. It may push her to abandon sobriety entirely.
12-step meetings are meant to be as supportive as possible. Everyone who wants to quit should feel welcome. Making unwanted advances on new members endangers the reputation of the group and possibly all groups. It only takes a few high-profile cases of harassment and exploitation to tarnish an entire organization. The last thing you want is someone thinking about going to AA but then remembering a story about creeps at 12-step meetings.
It’s hard to say how common 13th stepping is, but most people attend meetings to focus on recovery. It’s important to remember you don’t have to do anything that makes you feel uncomfortable. You are free to choose your own sponsor and it’s better to choose someone of the sex you aren’t attracted to; if someone tries to assign a sponsor to you, something is wrong. If you feel uncomfortable at one meeting, try another. Most areas have many to choose from. There are meetings for men only and women only. Some areas have LGBT meetings. Find a meeting where you feel safe.
You are of course free to enter a relationship if you want to, but most people recommend staying sober for a year before getting involved with someone, especially someone else in recovery.