ahem
The Serious Crime Act 2007, Section 44 (Intentionally encouraging or assisting an offence) wrote:
A person commits an offence if—
(a)he does an act capable of encouraging or assisting the commission of an offence; and
(b)he intends to encourage or assist its commission.
http://www.legislation.gov.uk/ukpga/2007/27/section/44
By your own admission, you are doing "an act capable of encouraging or assisting the commission of an offense", and again by your own admission you "[intend] to encourage its commission".
If you actually expect that someone will do it, then Section 45 gets you as well.
The Serious Crime Act 2007, Section 45 (Encouraging or assisting an offence believing it will be committed) wrote:
A person commits an offence if—
(a)he does an act capable of encouraging or assisting the commission of an offence; and
(b)he believes—
(i)that the offence will be committed; and
(ii)that his act will encourage or assist its commission.
