Children of Lesbian and Gay Parents.....No data are available regarding gender-role behavior for children of gay fathers. ...
Golombok and Tasker (1996, 1997) studied 25 young adults reared by divorced lesbian mothers and 21 young adults reared by divorced heterosexual mothers. ..... These results were based on a small sample, and they must be interpreted with caution.
Also, under the same link:
Since the incidence of homosexuality is about 1%, this would suggest that kids of gay parents are ten times more likely to be gay..... Bailey and his colleagues (1995) studied adult sons of gay fathers and found more than 90% of the sons to be heterosexual.