We started swinging way back in the mid 70’s and were really into the party scene, as for the women having their monthly visitors, one of the wife’s girlfriends (a fellow swinger) put the wife onto the lurk where if their was a big party coming up and her monthly visitors were due she would go to the Doctors and tell him she was due and we were going camping and she did not want to be bothered with her periods and he would put her on the pill (their was no need for the pill contraception wise as she had her tubes tied).
Later in life she had a hysterectomy so she had no monthly visitors, we eventually wound down to her being a hot wife “going with other guys” and her having other lovers where we would have M F M threesomes as we got older. We are both retired now and don’t play but we did enjoy 25 + years in the scene all bare back sex and never caught an S T D and have survived to now being married 46 years and still very much in love.