Is this still adultery?

[definitelymaybe8]

We have officially separated, still live together, but if my DH is having a relationship with another is this still classed as being adulterous or is he as he says not answerable to me any longer?

If you've separated I would say no but legally it is as you're still married.

For legal purposes it would be adultery, though he'd have to admit it was happening for the divorce forms to show that [or you'd need undeniable evidence]. Has to be a sexual relationship, between a man and a woman, of course.

Unless the Partner who is committing Adultery puts their hand up and admits it is hard to prove. Even if you had photos of them together and copies of hotel bookings it does not prove conclusively that Adultery took place even though it is a good bet as to what has happened.

Not sure in this case as OP is already officially separated, but if you live with someone for 6 months or more after the alleged adultery then it can be deemed as acceptance?

It doesn’t matter anyway. It makes no difference to the settlement. He can do whatever he wants and may well lie about you too. The law doesn’t care.

Legally is adultery yes