Your S is old enough to work out his own R with W. Getting in the middle is both controlling and triangulation. You will end up damaging your R with your son. So get out of the way and let them work it out.
Plus it doesn't work. You can't force love and respect as it is something given freely. And teenagers have to come to grips with cognitive dissonance in their own way.
Never tell a child your other parent loves you it puts you in the position saying absolutely something about another's feelings you don't know and it invalidates your child. I think you can say I think or I believe that or your other parent told me. However I can see you are struggling. That is talk it through.
And children should have a loving R with both parents is your belief and it may not be true.
This stuff has a way of unfolding in time.
This isn't to punish W, nor to alienated S from his mother. It's the opposite.
Think of yourself as Switzerland, listening and supporting.
V
Freedom is just another word for nothing left to loose. V 64, WAW