Good luck urmila.
Generally it is found that primary/secondary does not hinge on love, per se, but on shared living space, finances, child care, insurance. If your cousins will be living in a separate apartment, paying their own rent and utilities, and things like that, it simplifies things. Will you share cooking, cleaning up, bedrooms on a regular basis? Or will you have 4some time and then each couple retreats to their own apartment and bedroom at the end of the day?
It will all depend on how things play out for the 4 of you whether your cousins remain secondaries, or become co-primaries. I assumed you've known at least one of this couple all your life, since you are cousins. Have you been in love with him or her for a long time, even longer than you've known your husband?
Are you all bisexual or are you all straight? Is your husband in love with both of these people?
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
Mags, F, 60, poly-dating, loving and living with
miss pixi, F, 38
Punk, 41, M
Old Friend, gender fluid
Nick, 35, M (occasional lover)
Hippie, 25 (?)
Dark Wing, 45 (?)