Oh Hey..I'm sorry. I know you are probably totally in love with this man but please....look to me as the lady with the Crystal ball and I will tell you how this goes.
She is difficult now in pregnancy, just wait until the baby is born...bam! There goes any libido she had along with any feelings of body confidence or energy to do her hair. It will all be about the baby and she will be doing 90% of the work, especially if she is breastfeeding (which she should be because, yanno, it is for the best). He, on the other hand has no hormonal shift affecting his hormones, he has just the same libido as before and you know how will be receiving all that lovely libidinous attention, yes you! So, what it will look like to Mrs. Feeling Fat and baby obsessed is...she is exhausting herself taking care of his baby whilst he spends his time f*cking!
I know it will be an over simplification, I know both of you will try to help and I know you all, not just her, will be exhausted too but...I also know what it is like to be a mother of a new baby.
Mine is 22 weeks tomorrow, after climbing the walls in sexual energy all throughout my pregnancy, my libido disappeared the day she was born and it has not come back yet. Same thing happened the last time, frankly the baby is just more interesting than sex and I just don't fancy it and whilst every mother is different I know that varying periods with a lack of libido is totally common and it is probably more safe to factor that in, than imagine it won't happen.
Secondly, a baby makes you turn into a She -Bear, you will do anything, say anything to protect this precious little bundle from stress and drama, if your presence is causing stress, this couple WILL close ranks on you and again you will be out on your ear, they have done it before and you considered coming back so they know they can do it again with no risk to themselves and if they want you back later all they have to do is bid you come hither.
You are expendable to them. Do not allow yourself to be treated that way for a bit of male attention, it's not worth it. Good Luck whatever you decide to do.