Yes, that was during the Acts of Vengance story where Magneto was being turned into a villain again not his best moment but not really a he was totally manipulating her either given the one actually doing that was inmortous.
Mags was there during the thanksgiving party but also the birth of the twins, there´s even a scene where he feels let down because she gave them names from Vision side of the family, lol mags srs but was happy he was allowed to be there at all.
But they are not her biological father, that´s a conflict of a whole other nature, well now he´s her former biological father but still. but well I have to go and I just wanted to leave my two cents on this issue.