URGENT! OW had an abortion, H miserable

[ourcrisis]

A little background first:
good/boring marriage before.
A started in May. I found out in Oct. DH refused to
have a clean cut and was planning to leave.
Started in Nov I started DBing and requested his PA
turned to EA. He agreed. Since Nov, DB working quite
well and he did not leave though he still see OW
about once a week. I thought we were getting close to the
part where he would break up with her.
(Yesterday night he told me what I am writing below)
2-3 weeks ago he found out she's pregnant. At some
point he told her to get an abortion. She did it last Sat.
Now h is feeling VERY GUILTY. This is against his values.
(Note: readers, you may have different opinion on this
issue but please for now don't judge him or ow on this).
He wanted to spend more time with her now to make sure
she's OK through this period.
I am at a loss as to what to do now. As a woman, I
do feel for her having to go through this. If I were
a stranger or her friend, I would definitely spend
lots of time with her. But as the spouse, I am very
afraid that if h spends more time with her, she will
get the wrong idea or both will get back into
a deeper relationship. But I also feel h has an obligation
to see her through this. Yet I don't want him to be her rock
at this time. It's probably not good for her to hang on
to h if eventually (hopefully) he comes back to me.

What do I do now?
Do I let him see her lots?
Do I set a time limit? (which I know h will not set, not his style)
Do I not let him go out a lot? (which is probably against
both our moral code for both h and myself)
Crazy idea. may be I go with h and help her out together?
(not sure how this can be done at all)
Anyone gone through this or have a good idea?

Also, h is very stressed. any idea on how to behave around
him at this period?

Thanks. I am so lost. I am having very mixed emotions now.