The particular delusion isn't named, but it's purpose is, binding these over to condemnation. Romans 1 describes a similar circumstance:God's point:
2 Thessalonians 2:10-12
10 and with all unrighteous deception among those who perish, because they did not receive the love of the truth, that they might be saved.
11 And for this reason God will send them strong delusion, that they should believe the lie,
12 that they all may be condemned who did not believe the truth but had pleasure in unrighteousness.
Romans 1:28 KJV
And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient;
They did not receive the love of the truth. They did not like to retain God in their knowledge. So God gives them over to their vile affections, men with men, and women with women.
This is directly contrary to the first truth spoken by God regarding mankind.
Genesis 1:27 KJV
So God created man in his own image, in the image of God created he him; male and female created he them.
We are created in God's image, and have been created male and female.
Is this Lie, that they will believe so as to be condemned that we are not created male and female, but that we are whatever we want to be? Then given over into that delusion?
Much love!