Relationship born out of love, dies unknowingly.
As time has revealed; both of you have separate agenda - one that
refuse to break up due to the fear of the repercussion and the
other clinging onto a past love.
Eventually, it's not a matter of the questionable child; it's a
matter of a soured love that deception has taken roots in. And
deception will surely kill [Third Law of the Old World (CloUdiSm)].
Most of the people here have engaged a moralistic view of how this
child should be treated, but when love is missing -
everything else is a mistake. Your child, mine
child, his child, nobody's child... all becomes mistakes, it
doesn't matter.
When love is present, all becomes acceptance.
You can delay deception's effect, but it will get to the heart of
the relationship and leech life out of it. Delaying is only
delaying the inevitable - a intense break up will surely happen,
when the right planetary trigger strikes. Both parties are like two
suspicious state, anticipating each other's move and scheming ahead
of one another.
What kind of relationship can one foresee out from such warring
attitude?
Different people with different agendas, coming together for a same
relationship - what rubbish.
Think about this; whether abortion or not - this relationship is a
definite doom right from the beginning. And because this topic is
strictly about the relationship, I will not discuss the ethics of
abortion because (I repeat) ultimately, aborting or not will not save
the relationship. The child cannot save their
relationship and in fact, the child WILL become a playing chip in
this triangular game of three.
binarynwitz suggested PI - but since you two ain't married, what's
the use of the evidence presented by PI? It will STILL end the
relationship, isn't it? In the end, it is still back to square one
- An inevitable break up.
End it. 
Cheers
