I enjoyed very much a 10 year relatonship with a bi guy. Our mothers introduced us. Hadn't he died, I'm pretty sure we'd still be together today but I don't know if our relationship might have evolved had he ever the urge to marry a female. He did start getting close (beyond just sexually) to one while we were best buds (my term for a partnership) but dumped her when she presented the ultimatum between her or me (I didn't even get involved in that, knowing where my bud's loyalties lay). We were in our 20s & 30s at the time and both very playful, so having fun with others in bed with us was normal for our relationship.
As much as I still love him (sucks being in love with a dead guy), I don't know if I'd initiate a similar relationship today. So, while I suspect by some things you have said that you are, I'm going to ask, are you capable of falling in love with a man? If so, does being married to a woman and raising kids ("focusing 2000%") mean that even though you are bisexual, a guy has no chance of a committed, whole relationship with you, but that they should just be satisfied with being your sexual sidedish? Could you ever see yourself in a true threesome (however that might configure), giving 3,000%, with the guy getting his 100% too?