Hi
"I just would love to understand why they got married in London instead of their home town."
On 1891C there is a son John H (3m) with them in Wokingham (15 Milton Road).
He a solicitor-38y, she -30y.
They married June 1890
John H registered Q1 1891 Wokingham 2c 398
Hmmmm, is that another reason?

You have the actual marriage cert? What are the full details on it?
Joking aside, there could be a valid reason ...............
Deaths Mar 1893 Henry Trower Roberts 40y Wokingham 2c 269
Ray