Before starting, I would like to clarify that my brother and his partner are in an open marriage. they are very open to seeing other people.

2 weeks ago, I was at the hospital to see my (28F) step mom (25F) giving birth. My brother(34M) and his husband (24M) were there, along with my biological mother (52F) and my father (65M) however, my younger brother (14M) wasn't present I guess they were traumatised since, at his birth, I passed out and had to be carried out of the hospital when i was his exact same age. Anyway I feel like I'm going on a tangent, so I'll get to the point. I have always been infatuated with my brother's husband he's buff but lean and tall, with blue eyes, mullet and a great mustache. Now obviously I wouldn't usually do anything with him since he's my brother's husband and all. It's limited to fantasies and some gossip with my besties. However that was all it was untill one day, my friend Juila's (28F) sister Clara (19F) recomended I should make a move on him and that he would probably go with it. In hindsight I shouldn't have listened to her advice given she's much younger than me and too inexperienced with these things, but I didn't think of it that way back, she fed my fantasies and illusions and I thought she was making sense. Also -maybe just for shits and giggles- my other friends (25-46F) agreed with her. Anywho, when we were in the hospital, I was feeling a bit overwhelmed so I decided to go out for some fresh air and my brother and his partner joined in for a smoke. we got to talking about my love life and how I was feeling a bit lonely and I was cheated on very recently by my now ex-boyfriend(36M), which somehow got us talking about sexual orientation, and it turned out my brother's husband has never had a straight sexual experience as he got married to my brother pretty young. After a 20 minute conversation, the nurse came asking for my brother for some paperwork to fill. Which left me alone with a guy i'd been dreaming and fantasizing about for a reallly long time, and having just discovered he's always been interested in trying out a heterosexual experience. I have to admit now, that back then I was a bit out of it, with my friends motivating me and my fantasies running rampant I made my move, and he seemed a bit against it at first but after some insisting he went along and it's like I flipped a switch, he was a completely different person at this point, taking the lead grabbing my hair... head, so on and so forth... I don't want share the details. All of this happened behind a large tree on the balcony, maybe it was the fear of being discovered that pushed us to this point or maybe we just both really liked each other, nevertheless, somehow we actually weren't discovered but due to guilt and a very gut wrenching feeling of betrayal I confessed a couple of days ago after waiting for the baby hype to die down. Surprisngly, me coming clean and admitting got my family mad unlike what I had in mind. I felt like if i just the say the truth they would forgive me and blame it all on him, but instead they say I emotinally abused him and took advantage of his vulnerability. I admit i was insistent but he was against it only for the first 15 minutes. I really think I did something wrong which is why I admited which should clear me of any guilt and responsability since they are infact in an open relationship. I’m taking a break from them and considering getting back with my ex to get my mind off of it.