I have been to seveal weddings/wedding receptions over the years where the bride and groom had serial weddings. The first was when we were in college. One of my husband's best friends got married at college (where we were student). I think they "eloped" at the courthouse. About 6 mos later, his parents had another wedding and reception in their hometown. They have now been married 28 years.
Then, another of my husband's friends did the serial wedding thing. They got married at the courthouse, then a second wedding in S. America somewhere where his wife was from. (I can't remember where, but, I think Columbia). Then, they had the big Catholic Cathedral wedding when they got back to the US. We weren't invited to any of them, but, we brought a gift.
The one that really galled me, though, was when my husband's boss had a "serial wedding" and reception at which they showed the video tape of their wedding in Las Vegas. It galled me more because it was on my birthday, and my husband felt compelled to go to this "wedding", instead of just sending a gift.