Yes, if the gender ratio is very imbalanced, it wouldn't be impossible for men to have had more partners on average than women. In fact it couldn't be equal, si

Yes, if the gender ratio is very imbalanced, it wouldn't be impossible for men to have had more partners on average than women. In fact it couldn't be equal, since the total number of partners would have to match. But the ratio of heterosexual men to heterosexual women is close to 1:1 and not 7:4. Therefore the disparity in reported numbers is impossible.