After the stone experience she had an affair with him, at least that is how I remember it. All of this was after Young's TJ affair.
Telford just repulsed me.
OK, that's how I thought it went, but, since I watched S1 fairly passively, I thought it might have gone:
TJ and Col Young
Wife got revenge with Telford but continued punishing Young for TJ (And Col Young didn't know about Telford yet)
Telford carried Young via stone and had Mrs. Young
Col Young found out Telford had already been having himself some before the Stones
So, yea, I guess she did Telford for Col Young and enjoyed it, so she decided to keep on doing him, without Col young