My wife is having a baby and I think it's her brother's

My wife and me have been talking about her having sex with some other man but she didn't want it to be a total stranger due to not knowing what they may have or who they had been with.
My brother in-law who just split from his live in girl friend moved in with us until he could get his own place. Well we had been drinking and smoking a little of my home grown stuff which gets my wife so fucking horny that she sat on her brother's lap asking him how long he had gone without getting any pussy. He told her it wasn't any of her business to which she said that if he wanted her tonight that they should head for our bedroom.
He told me the next day he just wanted to see how far she would take it before chickening out. Well when they got to the bedroom with me following she turned to him and said strip brother or I will do it for you. He told her he wasn't stripping for her so she dropped to her knees and grabbed his belt. He laughed thinking it was a big joke until his pants with his jockeys hit the floor and my wife had her brothers cock in her mouth sucking away on him. He looked at me and said you cool with this and I just said whatever she wants.
She had him hard in no time and stood up stripping her clothes off in front of both of us. She told her brother that she wanted him to eat her first and he looked at me again before getting between my wife's legs licking both of her thighs before driving in and eating his sister out. In only a minute or two my wife was grabbing his hair yelling that she was coming and for him to keep eating her.
She had only ever came once for me from eating her but she was coming like mad all over her brother's face. He climbed up and slid himself home inside my wife bareback. I said "Honey he don't have a rubber on. Honey he needs to put on a condom sweetheart."
All she said was "Fuck me bro, fuck me hard give it to me." I felt powerless to do anything but watch. Her brother had her coming quickly and often like she never did with me. She would say "Fucking my bro I'm fucking my brother and its so dirty. Harder bro fuck me harder." As she would cum again.
He told her he was getting close and she yelled at him to do it in her, fill me with your cum is what she was telling him. I stood there the whole time watching my wife go nuts on her own brothers cock. I guess I was kind of shocked at what took place before my eyes then I felt something wet on my thigh as I had cum in my pants and don't remember doing so.
That was the first of many and I mean many bareback fucks for them and times I would get home from work to find them fucking like bunnies in what ever room they happened to be in at the time.
Well that started in Dec. and my wife is now 3 months pregnant and saying that it could be mine just as easy as it could be her brothers and in any case she's having it and naming me as the father. I'm not so sure the kid will be mine cause her brother up to that point fucked her around 5 or 6 times more often then I did so the odds are its his.
The only good news is he's moving to the other coast once this virus thing clears up and it can't happen soon enough for me.