Update
I have been researching this and it appears that the whole matter hangs on the definition of "the sons of the bridechamber" which is not obvious to me:
KJV Luke 5:34 And he said unto them, Can ye make the children of the bridechamber fast, while the bridegroom is with them?
mGNT Luke 5:34 ὁ δὲ Ἰησοῦς εἶπεν πρὸς αὐτούς μὴ δύνασθε τοὺς υἱοὺς τοῦ νυμφῶνος ἐν ᾧ ὁ νυμφίος μετ’ αὐτῶν ἐστιν ποιῆσαι νηστεῦσαι
It appears that "bridalchamber" is only from Tobit:
νυμφών nymphōn, n.c., bride’s chamber. 4× +NT +AF English Gloss bridal chamber (3): Tob 6:14; Tob 6:14 (var.), 17 (var.) brides chamber (1): Tob 6:17 (2012). The Lexham Analytical Lexicon of the Septuagint. Bellingham, WA: Lexham Press.
I found nothing in the Jewish Encyclopedia to suggest that "sons of the bridal chamber" is a thing.
"Sons of the bridechamber" seems to be unique to the gospels. So what does it actually mean?
So before answering the original question, one would have to establish what a "son of the bridechamber" actually is!
Original question
Jesus refers to the Twelve as "the children of the bridechamber":
[Luke 5:33-35 KJV] 33 And they said unto him, Why do the disciples of John fast often, and make prayers, and likewise [the disciples] of the Pharisees; but thine eat and drink? 34 And he said unto them, Can ye make the children of the bridechamber fast, while the bridegroom is with them? 35 But the days will come, when the bridegroom shall be taken away from them, and then shall they fast in those days.
Thayers has this:
...οἱ υἱοί τοῦ νυμφῶνος (see υἱός, 2), of the friends of the bridegroom whose duty it was to provide and care for whatever pertained to the bridal chamber, i. e. whatever was needed for the due celebration of the nuptials: Matthew 9:15; Mark 2:19; Luke 5:34 ((Winer's Grammar, 33 (32)); Tobit 6:13 (14), 16 (17); ecclesiastical writings; Heliodorus 7, 8);
Am I correct that such a designation precludes the designees from being the bride herself?
Possibly related:
CSB 2 Corinthians 11:29 For I am jealous for you with a godly jealousy, because I have promised you in marriage to one husband — to present a pure virgin to Christ.