The most common and most likely answer to this crossword clue is the 7 letter word HITCHED
I've seen this crossword clue in The Guardian
H
I
T
C
H
E
D
Buddy explains!

The straight part
We know that "Like Mr & Mrs" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case like mr & mrs = hitched.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HITCHED mean?
HITCHED verb- To pull with a jerk.
- To attach, tie or fasten.
- To marry oneself to; especially to get hitched.
- Contraction of hitchhike, to thumb a ride.
- To become entangled or caught; to be linked or yoked; to unite; to cling.
- To move interruptedly or with halts, jerks, or steps; said of something obstructed or impeded.
- To strike the legs together in going, as horses; to interfere.