2C1R-in-law

1- Second-cousin-once-removed's spouse.
2- Spouse's second-cousin-once-removed.

My 2C1R-in-law is a good person.

co-2C1R-in-law

Spouse's second-cousin-once-removed's spouse.

My co-2C1R-in-law is a good person.

2C1R

Second-cousin-once-removed.

I don't know my 2C1R.

2C1R

Second-cousin-once-removed.

My 2C1R is a good person.