Dear El:
I wonder if your ex bf (or present bf)- if he called you confessing of his love for you right after he found out the other girl is pregnant, or soon after, because he felt fear, fear of the consequences of what happened. Maybe pay attention to his character: is the multiple partner preference of his, maybe it is not just a phase but his real preference. Maybe this is how he prefers things now and in the future and he feels safe with you because you accepted it (as a phase). Are you willing to accept this behavior, multiple partners on his part, as “business as usual” if and when you are back with him long enough?
As far as what to say to people who bring up the Facebook thing, you can say what you stated above in this post: “This is an innocent child’s life… I want (this child, at the least) to be happy.”
* You wrote that you want everyone to be happy in this situation- I don’t see how it is possible. It may be an unrealistic expectation and all your efforts to achieve something that can NOT be achieved will be wasted.
anita