This is also my situation. For anyone interested -
Dc1 was born of an abusive relationship when I was a teenager, relationship ended when DC was a very young baby, no contact since, no maintenance etc. Turned life around then met dh who became father to DC1 and we had DC2 together.
Happy enough for a few years but unfortunately we began to grow apart and seperated amicably. Exdh has both DC's just less than half the time and we get on well.
Met current dp, after a few years decided to have 1dc together. So quite big age gap between first two and three, but all good, everyone happy and getting on. Have been sterilised so no more children 😁 I like to think dp is forever now but not naive, you never know.
Life is not black and white and things don't always go the way you'd planned. People might assume things when they hear '3 by 3 men' I don't particularly care, I've made the best out of every situation and we're all doing well!