correspond

To be equivalent or similar in character, quantity, quality, origin, structure, function etc.

Coordinate term: equate

To exchange messages, especially by postal letter, over a period of time.

I've been corresponding with my German pen pal for three years.

To have sex with.

He pleaded guilty to the charge, so far as acknowledging that he had corresponded with other women lately, in order to get the better of his affection for me, but the experiment had failed, and he found that he should be for ever miserable.

When a Babylonian and his wife had a mind to correspond, they always first lit up the fuming pan, imagining it improved the passion.