OP_RETURN with Multisig
If this is what you are proposing:

Address A: 1Axyz...
Address B: 1Bxyz...
Address C: 1Cxyz...

Tx1

A -&gt; Multisig requiring 1 of 2 signatures from pubkeys of B &amp; C

Tx2

Tx1 output 0 -&gt; OP_RETURN


Then yes, that's totally legal on the blockchain. Not sure why you would want to do it, though.