TL;DR Found a married Bi Woman who is interested in me

Ok, I’ve cross posted this in other groups but maybe this specific one will help. I’m a 41F married to my husband for 14 years but we’ve been together for 20. Obviously a very long time. He knows I’m bi, and has always said he’d “be ok with me bringing home a girl”. Well it never happened like that when I’d go to a bar, but a few weeks ago I went out with one of my married friends that I knew from school and she works in my building. I was having a shitty week and suggested the gay bar so I could go dance and “make out with some strangers” which was my way of telling her I am bi. I never expected her to say it back, let alone suggest that I make out with her. But after talking about it with her, we both realized we were into each other and wanted to take it further. She’s had experience with this before but I have not. I just kissed one of my bi friends (while my husband happened to watch). So here I am 12 years later and not knowing how to approach the topic with my husband. Aside from me saying repeatedly that he’s under a lot of stress lately, he doesn’t seem very happy with me in general, meaning I just annoy him more than anything. I don’t want this new relationship to go away because I do deeply care for her and this has been the best two weeks of my life in the longest time. But I don’t know how to do what I need to without my husband accusing me of being crazy or going through a phase of some sorts.