"It can be important to have a plan of action for how to deal with the toxic behavior of your relatives," Dr. O'Neill tells Bustle. "Being prepared to deal with toxic behavior can help you to feel more in control of the situation." If your toxic relative is the controlling kind, giving them a specific area of the wedding to arrange — and nothing else — can be a good way to keep them involved while limiting their ability to do damage. Let them wrap the wedding favors, or hang the string lights. This is a strategy that works on toxic people who have an efficient streak — and those who need to be the center of attention, or at least involved, and throw tantrums if they feel excluded.

For a better experience, keep things very limited: instead of "organize the bridal shower", for instance, ask them to take measurements of the venue (once you've booked it!), or confirm menu requirements.

This Won't Work For: Toxic relatives who like to take over everything in sight. Those people may need to be excluded from planning altogether.

This is one for the wedding and reception. If your toxic relative tends to act out at parties, it may be a good idea to ask a collective of understanding friends or relatives to keep an eye on them and figuratively sit on them if they start misbehaving. You're getting married; you can't do it and nor should you. "If your mother or father is the toxic person," therapist Cynthia Catchings tells Bustle, "limit the time you spend with him or her and identify other relatives in your family who can offer an ear. This is also your partner’s opportunity to stay involved and create a stronger bond between the two of you."

It's a big responsibility, though, so think hard about who you choose to do it. Toxic people who need managing, perversely enough, often have a good sense that they're being managed and can make life really sh*tty for those who are doing it.

This Won't Work For: relatives whose problems aren't centered around acting up in public. If they're behind-the-scenes awful, babysitters aren't necessary.

The "line managers" control the boundary between you and the toxic person through interception. Often, future spouses and other family members are the best people to do this; they can say things like "can't come to the phone right now" and "currently doing a tasting, will circle back." This is a good approach for "good girl/boy" toxic relatives, who don't want to look bad in front of others. If somebody else intercepts their issue before it gets to you, the relative won't take it out on them.

"This does not require for us to stop seeing to speaking to the person," Catchings tells Bustle, "but diminishes the opportunities for them to hurt us."

This Won't Work For: Toxic relatives who will vent their spleen at whoever gets in the way. Nobody should have to take that, including you. Make sure everybody involved is practiced at just putting the phone down.

Here's a key issue with toxicity: often, other people can't see it, or don't want to. If you're planning a wedding, though, you need other people to see it. Enlist everybody in your family who understands the issue, whatever it is. This is a situation in which you will need to feel less alone. "If no other relatives are available, contact a friend or coworker you trust," advises Catchings.

This Won't Work For: Families in denial. It sucks, but there are some relatives who just refuse to see what the issue is. In which case, your support needs to come from elsewhere, such as a group of understanding friends.

Weddings are a great time to start understanding your ability to say "no." That can be very tricky if your toxic relatives are in some way paying for the wedding; but it's worth remembering that some things are not worth the price. If you can, negotiate very firmly on what they can and cannot have a say on. That way, if they break that line you can tell them (kindly, but seriously) that they're outside their zone, and that it's not their concern.

"Be assertive! Be polite! Most of all, be able to say no to demands that feel unreasonable," says Catchings. "This is your wedding and be it during the preparation or during the great day, you are the one in charge. Never forget that."

Establish no-go areas as soon as you can: passive-aggressive behavior or interference are just two examples. And if they cross those lines, give them effective "punishments," whether it's walking out, cutting them out of the conversation, or removing them from the planning process. "It’s okay to leave a situation, it’s okay to walk away, it’s okay to say no," says Dr O'Neill. "Your wedding day is about you. Focus your time and energy on the people who are there to celebrate you and your partner."

This Won't Work For: This is uncomfortable for everybody, but it's one of the most necessary steps for dealing with every kind of toxic parent. Make this an essential element.

Weddings and their planning are chock-full of shiny things that can be used strategically to get toxic behavior off-track. Toasts! Confetti! Picture-taking! Ritual is a helpful thing; throwing up new ideas and things that need doing can derail problems and cause a toxic train of thought to peter out.

This Won't Work For: Sulkers. Toxic relatives who like to play the martyr will refuse to be distracted from their bad mood, even for big parts of the wedding or the planning process; it's part of their routine to try to be cajoled out of it and refuse. These people are best left alone to sulk in peace.

Even if it's an intensely busy day, it's important to make sure you're OK. "Find some space," Dr O'Neill tells Bustle. "Even if it’s just for a few minutes or so, step outside, find a quiet nook, or anywhere that you can take some deep breathes and reconnect with yourself."

And if that's proving difficult, she says, adopt a mantra. "Give yourself a slogan for the day, a mental cue that you can repeat throughout the day," she says. "For example: 'today is my day. I deserve happiness. I will work to give myself happiness today.' At different points throughout the day, find opportunities to repeat this slogan to yourself."

Everything in place, all strategies tried, and your relative's still ruining everything? It's OK to cut them out. If they keep crossing lines and refuse to treat you properly through the planning process, consider rescinding their invitation. It's your event, and the presence of anybody beyond the people getting married and the person marrying them is technically superfluous.

"The first thought, and perhaps the most difficult way to shield ourselves from toxic behavior, is to limit or cut off entirely, contact with people who regularly attack us in different ways," says Catchings. "However, that is hardly ever possible." Instead, she says, "we can arm ourselves with the basic skills that will allow us to survive and enjoy the great moment."

It's a serious step, but sometimes serious behavior with no redeeming features deserves it. If they keep threatening not to come unless you do X or Y, just take them up on it.

This Won't Work For: Relatives with whom you'd like to go back to "normal" (however dysfunctional) after the wedding.

Dealing with a toxic person in any situation and trying to manage their issues can make you feel as if you're the one causing a problem. It's not true, and it's valuable to remember that, particularly on a day that's focussed on love. "Remember that you do not owe anyone any explanations," Catchings tells Bustle. "Recognizing the traits that make that person toxic will also help you remember that it is them, not you, causing conflicts. Your wedding is about you. The toxic person might not know how to act differently, and you have no control over it, but you know you have control over how you think and feel."

No matter how your toxic family member behaves themself during the planning or the event itself, you have control over your reaction to it — and you can use it to help mitigate the impact your toxic relative may have on your day.