Oh yeah, and I wanted to add, seems to me your desire to be Beth's husband, instead of Mark being her husband, is a holdover from your fundie/mono brainwashing as well. Competing males! Rawr! It's what the patriarchy is all about.
Mark doesn't own Beth, despite now being married to her. You wouldn't own her if she was your wife, and she wouldn't own you.
Wives as chattel was the norm back when the Bible was written. Not now. Especially not if Beth is insisting on an open relationship with Mark-- but even if they were mono. Marriage is convenient, it gets you social recognition in many ways, and legal benefits as well, but as for the spouses, other issues can and should be negotiated as needed. Freedom to come and go, see friends separately, pursue hobbies separately, even have lovers, it's all up to you!
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 (poly, F, 61) loving miss pixi (poly, F, 39) since January 2009, living together since 2013
"Master," (mono, 36), miss pixi's Dom for 3 years