If you are looking for a long-term swinger lifestyle relationship with your partner, the requirements would be different. Before settle on the third person, make sure your expectations and boundaries.
Dos and Don'ts of a long-term three way relationship.
Make sure you know what it means to be in a tinder threesome relationship with your partner and how to make it work. When you decide to have a bi dating relationship with your partner, it is very easy for the couples to think that they are the leader of this relationship. If they are thinking like this, they can easily ignore the needs and feelings of the third person. Therefore, before inviting the third person in, you can have a talk about it first. It doesn't mean that the third person is just the same as everyone else in this relationship, but as soon as you put someone in an adverse condition, something bad will happen eventually.
Do not try to find Unicorn. If a couple try to look for a third person to co-create a harmonious world and they both have the superiority complex, they can easily fall into the trap of looking for a unicorn: a person who provide everything the couple want and doesn't need any return. They are not looking for a human-being who have its' own rights and needs. It is impossible and also not right and not welcomed in that way. Unicorn is an independent bisexual woman who wants to date a couple. Unicorn is like a mystery and very rare to find. Therefore, prepare for a long time searching.
Be nice and polite to the third. Just like in daily life, if it very important to think for other people. When people start to fantasized about their dreams, they tend to forget the etiquette. Especially when you are in a three way relationship and if you want to keep it steady and satisfactory, you need to be nice and polite to each party.
Involve the third in when you are talking about your expectations and desires. After you have settled on certain person, it is very necessary to have a long and nice talk together. You should set boundaries together and talk about expectations together. You should not impose your "couple rules" on the third person without him/her notified. This is only fair.
If you are worried that it might be unfair to have a three way relationship, you should try to hookup date another couple.
Do not do things you think are improper and do not encourage anyone to do something might be bad for other people. Do not do anything just to please other people. If you don't feel so comfortable with things you are doing right now, stop and talk with your partners until you feel comfortable. Now I think you are ready for your adventure. Go ahead and enjoy.