The first time, it was an easy decision. Being single past the age of fifteen was considered beyond the pale on Athene, a custom the Voyager away team had been unaware of before landing. Janeway quickly explained the situation to Chakotay, whom she had left in charge of the ship. The choice was simple, she said—acting as if she was already married to get the dilithium the ship sorely needed, or staying single and without coffee for another fortnight.
Chakotay had no recourse against her logic. It was not like she was asking him for his permission anyway.
At the end of the three-day negotiations, a proud, if slightly awed Ayala came back to Voyager with a wide smile on his face. Kathryn Janeway had a spring in her step which Neelix commented on several times within earshot of Chakotay. Tom swore he would never, ever again, go on an away-mission with Tuvok, before asking for two days off. It seemed that the Vulcan had run him ragged with his snoring. Tuvok explained he was not used to being in bed with somebody else than his wife.
After much reflection, Chakotay decided not to ask the captain about her sleeping arrangements during her stay on Athene. Within hours, he had Ayala transferred to the team permanently assigned to the maintenance of Deck 15. The man was never seen on the bridge ever again.
Chakotay also re-jigged the rosters so he would personally be part of every away mission the captain was assigned to.
###
The second time Tom got the short end of the stick. Literally.
It seemed the society Tom and the captain were visiting believed in strict obedience of the husbands to their wives. Remaining single was again not an option if the captain did not want Tom ending up third husband to the ruler. Chakotay considered that option at length, but thought better of it.
It soon became obvious from Tom's twice daily reports from Scythia that the stick was not just a symbol. The captain was meant to use it to reinforce her position in the eyes of the locals. Tuvok made it clear from his tactical console that, although those gender-biased mores were most deplorable and fortunately uncommon among Federation worlds, the captain was bound by Starfleet protocols to follow the planet's customs to the letter.
Chakotay found himself wholeheartedly agreeing with the tactical officer. He refused Tom's pleas to return early to the ship until the last of the food containers the captain had been bargaining for safely materialised in Voyager's cargo bay.
A week later and Tom still avoided being in the same room as Janeway, while she cackled every time she saw him.
Chakotay thanked his good stars that a bout of Vesuvian flu had prevented him from accompanying the captain this time. He also re-wrote the away mission instructions to include gathering information on conjugal and other such customs before landing.
###
Another planet, another tradition. Things were looking up for Chakotay's first official wedding to the captain, until the inhabitants of Cupid took a shine to B'Elanna instead. They decided this brave and beautiful and strong woman needed an equally strong and beautiful and brave partner to accompany her for the rest of Voyager's journey through the stars.
B'Elanna and the captain held hands and giggled through the ceremony, the afternoon dances, the drinks, the evening dinner, the speeches, and more drinks, before moving to the marital bedroom together.
Paris sulked the whole time. Chakotay was thankful he did not have to hold hands with him, although they had to share the same thin mattress in the corridor. Neither of them slept that night, the sounds coming from the other side of the door keeping them wide awake.
Back on board Voyager, Chakotay announced a ban on all females accompanying the captain on away missions. When Tuvok lifted an eyebrow, Chakotay told him that he did not want to see the authority of the captain weakened in any way.
Paris agreed with him. Great, thought Chakotay. Now they were into male bonding.
###
He quickly forgot the name of the society who insisted on trios. He now understood why Tom refused to go on any away missions with Tuvok. Both Janeway and Chakotay returned to the ship with blurry eyes, snapping at each other for lack of sleep. The captain spent the rest of the week recuperating in her quarters, out of reach of the Vulcan's snores.
Chakotay took Tuvok's name off the list of crew members allowed to go planet-side with the captain.
###
He had lost count at about the third-year mark. Whatever the customs of the Delta quadrant inhabitants, they always seemed to lead to the captain getting married to a crew member or to aliens of various gender combinations. Anybody else but him.
He was sure he was losing weight, while Janeway grew more radiant the longer the journey. It was all getting very frustrating.
###
By his own calculations, polygamous societies outranked monogamous ones by a factor of one to ten in the Delta quadrant.
He thought he might be cursed.
###
The time when the captain was asked to wed the entire council of an obscure world, all twelve councillors and their livestock, he revolted. He took her aside before she put a foot on the transporter pad, ordered the ensign to find Tuvok, and proposed on the spot.
"What took you so long?" she smiled, before kissing him.
The newlyweds sent Tom to the planet.
Inspired by 'Five Times Sam Gets Married' by CoraClavia to be found on AO3, although her fic is much nicer than mine.