@wynndela,
My inclination would be to not handle him anymore; I'd go for a new brand, as this one, seemingly has some major defects, Wynndela. Return it to the dealer and tell them that if they can't produce a better product than what you got, you'll have to seriously consider taking your business elsewhere.
But remember, I'm not there!
The reason I say this is that I find it's extremely odd that someone who is in such a committed relationship, someone who already has a son with you and another child on the way, should need the attention of another in such quick fashion. Love/commitment doesn't end simply because there are some problems.
Having said all that, there is a chance that you can still work things out with this lemon. But it'll take some work on your part and his.
I could tell you that it isn't important just because you are pregnant with one and have had another with him, but I won't. What I will tell you is that it isn't the overriding concern.
Don't take the product back just to get the product back. Try to keep at least one eye on the long run. Will this product really stand up to the years of trial and tribulation that occur in all marriages/relationships?
Will you just have to junk this one a few years down the road? Some tough choices that only you can make.
Good luck, Wynndela.