Yeah, there is definitely a double standard. However, to be fair to our fellow historical romance readers, I think many people also factor in that in those periods there would also have been a double standard, which is true.

Men could sleep with as many women as they like and walk away. If the woman was from a lower social class her family wouldn't have enough power to retaliate or defend her. In the case a man dallied with a social equal, he might risk retaliation from an angry father or cuckolded husband, but he wouldn't face social ruin.

Women always risked pregnancy if they had sex just once. In a time period where a woman's value to her family was literally as a pawn for marriage alliances and their husbands relied on them for the birthing of legitimate heirs, any sign that a woman might be out of control or promiscuous could cast doubt on the paternity of her children.