Welcome, thank you for being here. Well, in my view, if one person asks to have an "open relationship" after they've started having a monogamous one, then my question to them is "Why aren't they getting what they need from the relationship?" and "Can the problems causing this drift apart be recognised and fixed?" or "Does this mean they are actually not suited to be with each other?"
There are some special circumstances where open relationships are needed i.e. some people love each other dearly but some terrible accident means that one is sexually incapable and the other is sexually frustrated. Or two people both cannot maintain a monogamous relationship to each other due to past trauma, which takes a long time in therapy to sort out and try to heal from, so they agree to see others as well in the meantime; to enable them to also still see each other without being frightened apart due to a fear of emotional commitment.
Now I have some other questions for you, firstly how old are you? Secondly how long have you been attracted to the same sex and were you ever attracted to the opposite sex or have you experimented? Thirdly and fourthly the same questions as the first and second questions except about your partner?!
All the best,