Marriage nullified, can mother change children's Surnames to Hers?

Good atty. my issue is this... My soon to be ex-hub is planning to file for marriage nullity due to 17 y.o lg kmi nong kinasal. I wont protest to it but I'm thinking is it possible to change our children's surname from his to mine? Kasi d ba magiging illegitimate na rin ang status ng mga bata eventually. So i might as well let them use my surname. Honestly what freaks me out over this is ung ex ko ung nagsala sa amin ng mga anak namin by having an affair but then sya pa ang my lakas ng loob to initiate the filing of annulment. Such selfish jerk. So in return im going to give him the totality of his selfist act by taking him out of my children's lives. BTW we have 4 kids.. 2 are already in college. Need ur advice badly. THANKS SO MUCH

Hi,

You said you got four (4) kids, how old is each child?

wats the reason for seeking nullity of your marriage by your husband?