Marriage of parents and baptism of son on one day?

[NicolaasMars]

I find the baptism of Frederick Wright Harvey, on 12 March 1832, in St. Martin-in-the-Fields. Middlesex. Parents are John and Amelia Harvey.

I find the marriage of what I believe to be these parents on 12 March 1832: John Harvey and Amelia Wright Maddison, married by banns in the Parish of St. Mary's Lambeth in Surrey.

I could (barely) imagine that a couple that got a child out of wedlock would marry on the same day as the baptism of their newborn, but why in two different churches? Or am I completely on the wrong track here?

[Milliepede]

Maybe someone else took the baby to be baptised while they got married?

Don't suppose it says how old the baby was?

[heywood]

No birth date for the child. Later baptisms took place in the same church.
Perhaps the marriage was in the bride’s family parish?

[Bookbox]

why in two different churches?

This isn’t so unusual. Possibly they didn’t want the clergyman marrying them to know they already had a child. Or they didn’t want the clergyman baptising their child to know they weren’t married.

[jonw65]

Third of six marriages that day at St. Mary.
Marriages had to take place between 8 a.m. and 12 noon.

12th March 1832 was a Monday